
An 'Islamist' suspect has been arrested in connection with the pipe bomb attack on Borussia Dortmund's team bus as authorities say they are treating it as a 'terrorist attack'.

German police searched properties belonging to 'two suspects from the Islamist spectrum' on Wednesday and arrested a 25-year-old Iraqi man from Wuppertal - not far from Dortmund - meaning another man is still on the loose.

The explosive devices used in the attack contained metal pins, one of which was found buried in a headrest on the vehicle, according to Frauke Koehler, a spokeswoman for federal prosecutors.

Ms Koehler said it was lucky 'that nothing worse happened', adding that investigators are still working to determine how the devices were detonated and what substance was used.

The second suspect is a German, aged 28, from Froenderburg, near Unna, also in the state of North Rhine-Westphalia.

They have both reportedly been on the police and intelligence services radar for affiliation to ISIS while it has been claimed that one of them was seen in the vicinity of the crime scene shortly before the pipe shrapnel bombs were detonated.

Elsewhere police said three letters claiming responsibility for the attack have been found, all of them saying that it was carried out in the name of Islam. Another letter claiming to be from the far-left group Antifa had been discounted as a fraud.

At least one of the notes made reference to the Berlin Christmas market attack, in which an ISIS fanatic drove a stolen truck into shoppers, killing 12.

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Police in Germany have arrested an 'Islamist' suspect over last night's pipe bomb attack on the Bourissa Dortmund team bus, and say they are investigating another suspect 'from the Islamist spectrum'

The Borussia Dortmund team bus was last night hit by three explosions while carrying the squad to their Champions League quarter-final against Monaco, with defender Marc Bartra taken to hospital with a broken bone in his wrist

Prosecutors say the bombs were filled with metal pins, one of which was found embedded in a headrest on the bus, saying it was lucky 'that nothing worse happened'

Police are still investigating how the devices, believed to have been hidden in this hedge, were detonated and what kind of explosives were used

Police also announced that three notes claiming responsibility for the attack have now been found, all of which say it was carried out in the name of Islam

The Borussia Dortmund players make their way on to the field of play wearing T-shirts paying tribute to their squadmate Marc Bartra

The dressing room at the Signal Iduna Park stadium bears the players shirts ahead of the postponed Champions League game

Borussia Dortmund's Roman Burki wears the shirt of Marc Bartra before the match, where they will face off against Monaco

German police searched properties belonging to 'two suspects from the Islamist spectrum' on Wednesday and arrested a 25-year-old Iraqi man from Wuppertal - not far from Dortmund - meaning another man is still on the loose. A broken window is seen at a residential house close to the team hotel

An armoured police truck was called in to help secure the stadium ahead of the UEFA Champions League quarter final tonight

According to Der Spiegel, that letter was written in German starts with the phrase 'In the Name of Allah, the Gracious, the Merciful' and ends with two demands.

First, 'tornadoes', a reference to German reconnaissance planes, must be withdrawn from Syria, and second the US base in Ramstein, Rhineland-Palatinate, should be closed.

Controversial drone operations against terror targets in the Middle East are controlled from the base.

The letter also claims that German combat aircraft are involved in killing Muslims in the 'Islamic State', adding that athletes and other celebrities 'in Germany and other Kreuzfahrer (crusader) nations' are now on a 'death list'.

Terrified stars dived for cover as three blasts sent shards of glass flying through their coach while defender Marc Bartra broke a bone in his right wrist and later needed surgery to remove 'foreign objects' from his body.

The coach had just left the club hotel ahead of their Champions League quarter-final clash with Monaco when the bombs were detonated in what is believed to have been a targeted attack.

A sniffing dog and its handler search the stadium in Dortmund, western Germany, prior to the postponed Champions League quarterfinal

Police remained on the scene today as an investigation gathered pace. The explosive devices used in the attack contained metal pins, one of which was found buried in a headrest on the vehicle, according to Frauke Koehler, a spokeswoman for federal prosecutors

Both suspects have reportedly been on the police and intelligence services radar for affiliation to ISIS while it has been claimed that one of them was seen in the vicinity of the crime scene shortly before the pipe shrapnel bombs were detonated

Police investigators search for evidence near the team hotel of Bundesliga soccer club Borussia Dortmund this afternoon

A policeman escorting the coach to the match on a motorcycle was also injured when the bombs went off in bushes nearby, having apparently been detonated with a mobile phone or garage door opener. The officer suffered hearing damage and shock and was unable to report for duty today.

German chancellor Angela Merkel said this morning she was 'horrified' by the 'repugnant' attack.

Dortmund has been a hotbed of radical Islam in recent years - Berlin Christmas market truck bomber Anis Amri attended a mosque there.

The club said today that Spanish defender Bartra will be out of action for 'several weeks' after being wounded in the attack.

Bartra had to have an operation on his arm and wrist but says it went well. The club said the 26-year-old will watch the Champions League quarterfinal match between his team and Monaco on television Wednesday evening and is keeping his fingers crossed for his colleagues.'

He wrote on Twitter: 'Hello! As you can see I am doing much better. Thanks for all your messages! All my strength to my team mates, fans and to @BVB for tonight!'

Police said last night they are hunting a car with foreign registered plates, which was seen near the crime scene shortly before the explosions occurred. UEFA said it would review the security arrangements for all of Wednesday night's Champions League matches.

The blast shattered the bus windows and the vehicle was burned on the right hand side.

'The bus turned onto the main road, when there was a huge noise - a big explosion,' Dortmund's Swiss goalkeeper Roman Burki told Swiss media.

Marc Bartra was injured in the explosion and was taken to hospital. He is pictured today with his arm strapped after surgery

Shocked Dortmund stars, including star striker Pierre-Emerick Aubameyang reported for training this morning. He is pictured arriving at the club's training ground today

Borussia Dortmund soccer player Erik Durm arrives at the training ground this morning just hours after the club's bus was targeted in a bomb attack

Players Marcel Schmelzer (left) and Nuri Sahin (right) arrive for training as an investigation into the blast continues this morning

Police said last night they are hunting a car with foreign registered plates, which was seen near the crime scene shortly before the explosions occurred

The game between Borussia Dortmund and Monaco at Signal Iduna Park was called off after last night's attack

A letter found outside the hotel 'takes responsibility for the act' and mentions the Christmas market atrocity in Berlin in which a truck driven by an ISIS fanatic ploughed through crowds of revellers killing 12. Police are pictured at the scene this morning

'After the bang, we all crouched down in the bus. Anyone who could, threw himself on the floor. We did not know if more would come.'

Burki said Bartra was 'hit by splinters of broken glass'. Dortmund's press spokesman said the 26-year-old had broken the radius bone in his right wrist.

The club said other players were safe and there was no danger inside the Signal Iduna Park stadium.

'The whole team is in a state of shock, you can't get pictures like that out of your head,' Dortmund CEO Hans-Joachim Watzke said.

'I hope the team will be in a position to be able to compete tomorrow on the pitch. In a crisis situation like this, Borussia pulls together.'

The team's Twitter confirmed the incident took place as the bus was leaving the team's hotel, L'Arrivee, a 12-minute drive from the stadium - Signal Iduna Park

While investigators do not yet know the source of the explosions, police have confirmed that additional 'suspicious objects' were found at the Dortmund team hotel in the wake of the bus bombing

Watzke, said police informed him that the explosives that went off near the team bus were hidden by the exit of a hotel and detonated as the bus passed.

The 'special' construction of the explosives should afford investigators some clues in determining who might be responsible, according to the German newspaper Bild.

While investigators do not yet know the source of the explosions, police have confirmed that additional 'suspicious objects' were found at the Dortmund team hotel in the wake of the bus bombing.

A German prosecutor said on Tuesday night that a letter found outside the hotel the team bus was departing from when the explosions happened 'takes responsibility for the act'.

Prosecutor Sandra Luecke said authorities won't give details of the letter at this stage, citing the ongoing investigation. The authenticity of the letter has not been verified.

Officers did not reveal the nature of the find but confirmed that a drone was deployed to assist in the search around the hotel.

Forensic experts searched the area where the explosion occurred in the hours after the incident

TIMELINE: DORTMUND BUS EXPLOSIONS 6.15pm (BST) Three explosions are heard outside the L'Arrivee Hotel and Spa as the Borussia Dortmund team make their way to their home stadium for their Champions League match against Monaco. The explosions smashed the windows of the bus and burst tyres. Dortmund defender Marc Bartra is injured with cuts to his arms from the shards of broken glass. 6.30pm Local police confirm a Borussia Dortmund player is injured following explosions near the team bus. Dortmund tweeted that a 'bomb explosion' had hit their team bus. They added that the injured player was 'in safety' and that 'there is no danger in and around the stadium.' 7.50pm Borussia Dortmund confirm defender Marc Bartra was injured and is being treated at a hospital and that the match was to be postponed for 24 hours. A spokesman at the already crowded stadium informed fans of the cancellation, saying that 'there is no reason for panic here at the stadium'. Dortmund recommended that fans stay in the stadium and remain calm to facilitate an 'orderly departure.' 8.05pm The chief executive of Borussia Dortmund Hans-Joachim Watzke confirms Marc Bartra's injuries are 'nothing life-threatening'. Dortmund police spokeswoman Nina Vogt says investigators do not yet know the source of the explosions that went off. 8.20pm Mr Watzke said the team 'is totally shocked' by the explosions that damaged the bus and injured defender Marc Bartra. He added: 'It's our task now to digest this somehow because it's only 24 hours before we have to play. That's our job.' 8.45pm Borussia Dortmund goalkeeper Roman Buerki said 'there was a huge bang, literally an explosion' that sent glass flying about on the bus. He added: 'We're all shocked. Nobody thought about a football match in the minutes after that.' 8.55pm Police in Dortmund say investigators 'are working on the assumption' that the explosions were caused by 'serious explosive devices.' 10.20pm The police chief in Dortmund Gregor Lande says it's not clear yet who was behind the explosions, but they believe it was a targeted attack against the Borussia Dortmund squad. He added that officers are doing everything 'to provide security and that will be the case tomorrow, too.' 10.30pm A prosecutor says a letter found outside the hotel the team bus was departing from when the explosions happened 'takes responsibility for the act.' Prosecutor Sandra Luecke says authorities won't give details of the letter at this stage, citing the ongoing investigation. Advertisement

Lange said officers are doing everything 'to provide security and that will be the case tomorrow, too'.

Gunnar Wortmann, a police spokesman, said: 'We will be working throughout the night to discover who was behind this attack. All police and vehicles in Dortmund have been mobilized.'

Dortmund Police Chief Gregor Lange told reporters late Tuesday that police decided at an early stage that the soccer team was the target of the explosions and are not excluding any possible angles in their investigation.

He said: 'We are assuming that they were a targeted attack against the Dortmund team.'

Three explosions detonating at the exact moment the bus passed by suggest a sophisticated expertise in both bomb building and detonation - perhaps using a mobile phone or a garage door-opening device.

But nearly three hours after the attack there were no real clues as to who may have been behind it.

Neither club has a radical fan following, leading to speculation it may yet be claimed by radical Islamist groups.

When asked about rumours of a blackmail plot against Dortmund during a press conference, police said: 'That's the first time we've heard about that.'

Shortly after the explosions, police confirmed that there was no immediate danger to anyone in and around the football stadium.

Police said in a statement they were working on the assumption that the blasts were caused by 'serious explosive devices', which may have been hidden in a hedge near a car park.

They didn't elaborate on the possible nature of the devices or say who might have planted them ahead of first-leg match between Borussia Dortmund and Monaco.

Explosive devices were believed to have been placed in a bush by the road along which the bus was travelling, according to German newspaper Bild.

'The explosive devices were placed outside the bus. Several windows were broken,' police spokesman Gunnar Wortmann was quoted as saying.

In a statement, Dortmund police said earlier that they could not say 'exactly what the explosion was or exactly where something exploded'.

'According to what is currently known, the windows of the bus were (entirely or partly) smashed and one person was injured,' Dortmund police said, adding that the incident happened in Hoechsten, located outside the city.

Several windows were smashed in the explosion, and Bartra, a Spanish national, was the only player to be taken to hospital.

Dortmund team spokesman Sascha Fligge says defender Marc Bartra was operated on late Tuesday for a broken bone and to remove 'foreign objects' from his body.

Bartra, the only player injured in the explosion, joined the club from Barcelona last year, and his former club were quick to wish him well.

'All of our support to @MarcBartra, @BVB and their fans,' Barcelona tweeted in support of their former player.

Spanish Prime Minister Mariano Rajoy also wished Bartra 'a speedy recovery' on his Twitter account.

Bartra, 26, joined Dortmund for eight million euros ($8.48million, £6.79million) last year from Barcelona, after coming through the Catalan club's youth system.

He has made 12 appearances for the Spanish national team.

Borussia Dortmund's managing director Hans-Joachim Watzke was quoted telling Sky TV: 'The whole team is in a state of shock.'

Monaco striker Radamel Falcao also sent his best wishes to the player and his club, tweeting: 'I'm sorry for everything that has happened. We are all well. I wish a speedy recovery to Marc Bartra.'

Dortmund also released a statement explaining what happened.

'Shortly after the departure of the Borussia Dortmund team bus from the hotel to the stadium there was an incident,' Dortmund said in a statement.

'The bus has been damaged in two places. One person has been injured and is in the hospital. At this point we will inform as soon as we know more.'

In the immediate aftermath of the explosions, Dortmund said there was 'no cause for concern' for those at the stadium, and added the club were in close contact with the emergency services and UEFA.

The stadium slowly emptied before Monaco players came on the pitch for a short training session.

Dortmund players stand outside the team bus after it was damaged in an explosion on Tuesday night in western Germany

Borussia Dortmund coach Thomas Tuchel is seen by the team bus after an explosion near their hotel before the game

Head coach Thomas Tuchel, centre, is surrounded by players after evacuating the bus following Tuesday night's explosion

Dortmund players check their smartphones as they stand outside their team bus following the explosion

Police officers stand in front of Dortmund's damaged team bus after the explosion on Tuesday

According to reports, explosions were heard as the coach went over a bridge six miles from the stadium

Monaco released a statement, saying: 'Faced with this difficult situation, AS Monaco wishes to express its full support for the whole Borussia Dortmund team and club.'

AS Monaco goalkeeper Danijel Subasic told Croatian daily newspaper 24sata: 'We are currently in the stadium, in a safe place, but the feeling's horrible.'

An announcement was made inside the stadium with a message put on the big screen informing supporters of the incident.

Tuesday night's match was cancelled following the explosion and has been rescheduled for Wednesday.

Following the announcement that the match had been postponed, Police Dortmund tweeted: 'To reassure stadium visitors and relatives: There are currently no indications of a threat to visitors in the stadium.'

Dortmund recommended that fans stay in the stadium and remain calm to facilitate an 'orderly departure'.

The club thanked supporters of opponent Monaco for their 'patience and understanding' and for chanting 'Dortmund! Dortmund!' when the reason for the postponement was announced.

President of Borussia Dortmund Reinhard Rauball (cenre) reacts on the reports at the stadium in Dortmund, Germany

Borussia Dortmund Hans-Joachim Watzke (second left) and President of Borussia Dortmund Reinhard Rauball (second right) talk with journalists as they react on the reports at the stadium in Dortmund

Police officers and firefighters stand outside the Dortmund team bus after it was damaged in an explosion

Dortmund police spokeswoman Nina Vogt said investigators do not yet know the source of the explosions

Dortmund's Pierre-Emerick Aubameyang, left, talks to teammates after a window of Dortmund's team bus was damaged in an explosion

#BEDFORAWAYFANS: KIND-HEARTED DORTMUND FANS OPEN THEIR DOORS FOR VISITING MONACO SUPPORTERS Kind-hearted people in Germany are offering Monaco fans a place to stay after three explosions hit the Borussia Dortmund team bus - forcing their Champions League match to be postponed last night. The explosions happened as the German club's bus was leaving L'Arrivee Hotel and Spa, about six miles from the stadium, Signal Iduna Park, for their quarter final clash with the French side. Defender Marc Bartra was injured in the explosion and was taken to hospital, the team said on Twitter, wishing the player a quick recovery. Last night's match was postponed following the explosion and has been rescheduled for tomorrow. And many kind people in Dortmund have taken to Twitter to offer their homes as a place to stay last night, using the #bedforawayfans Kind-hearted people in Germany have offered Monaco fans a place to stay after three explosions hit the Borussia Dortmund team bus - forcing their Champions League match to be postponed last night The campaign appeared to be a success as pictures emerged of visiting supporters in the homes of Dortmund fans Pictured are AS Monaco fans at the home of a Borussia Dortmund supporter Thousands of Monaco supporters made the 730-mile trip for the match and the majority were in the stadium before it was called off Thousands of Monaco supporters made the 730-mile trip for the match and the majority were in the stadium before it was called off. And many kind people in Dortmund have taken to Twitter to offer their homes as a place to stay for last night and today, using the #bedforawayfans. Vespafoto tweeted: 'Dear @AS_Monaco_ES fan. We have accomodation (sic) for for 5 people tonight to stay in Dortmund until tomorrow, just message me #bedforawayfans. Fischer said: 'I have space for 8 people. 15 mins away from the stadium.' The hashtag caught on and was endorsed by both clubs, with Dortmund saying: 'Dear supporter of @AS_Monaco_EN! If you need accommodation in Dortmund, please check #bedforawatyfans.' The social media site was also used with Monaco fans asking for help. Meanwhile, the chief executive of Borussia Dortmund, Hans-Joachim Watzke, said police informed him that the explosives that went off near the team bus were hidden by the exit of a hotel and detonated as the bus passed. Dortmund police spokeswoman Nina Vogt said investigators do not yet know the source of the explosions. Watzke said: 'It's our task now to digest this somehow because it's only 24 hours before we have to play. That's our job.' Advertisement

And Dortmund's official Twitter alerted Monaco fans to the hashtag #bedforawayfans as home supporters offered to put up supporters hoping to stay for the revised kick off on Wednesday.

Monaco also announced that it would give fans 80 euros (£68) toward hotel rooms for the night.

Police Dortmund praised fans for the way they dealt with developments, tweeting: 'High praise to all stadium visitors! Without problems almost all left the stadium and are on the way home!'

After the explosions, Dortmund players were transferred to the ground in minibuses and later made their way home on private cars.

'The team is totally shocked, that's clear. It's our task now to digest this somehow because it's only 24 hours before we have to play. That's our job,' Dortmun Chief executive Watzke said.

He added that there was 'no alternative' to rescheduling the match for Wednesday, as Monaco also has to play at the weekend and the return Champions League match is scheduled for next week.

'It's a very unfortunate situation but there was no other way,' he said.

Dortmund and German Football League (DFL) president Reinhard Rauball said it would be a 'bad thing' for the perpetrators to have any impact on the outcome of the quarter-final tie.

He said in a statement on the club's website: 'Of course this is an extremely difficult situation for the players.

Several of the players made phone calls as they stood outside the bus following the explosion

Dortmund's Marcel Schmelzer and other players speak to police officers outside the team bus after it was damaged in an explosion

Police escorted team members to an unknown location following the blast on Tuesday night

'But they are professionals, and I am convinced that they will put this away and will produce a performance (on Wednesday).

'It would be a bad thing for those who did this to succeed because the team is influenced in some way.'

The head of European soccer's governing body expressed shock over the explosive devices that damaged a team bus and left a player injured.

UEFA President Aleksander Ceferin said Borussia Dortmund and AS Monaco had made the right call by canceling their scheduled Champions League match after the incident outside the Dortmund team's hotel on Tuesday night.

Ceferin says he was 'deeply disturbed' to hear about the explosions and that the teams made the correct decision to prioritize the safety of fans, officials and players by postponing the game until Wednesday.

He expressed gratitude to the clubs, local authorities and supporters for their cooperation.

Gianni Infantino, president of world soccer's governing body, FIFA, called the events 'troubling'.

Infantino said: 'FIFA condemn the incidents in Dortmund. We are all awaiting further details of the incident.'

Borussia Dortmund put a message on the stadium screens informing fans of the incident

One fan looks concerned as he reacts to news of the bus attack as it is flashed on the screen

Several fans checked their mobiles and made phone calls following news of the explosion

One distraught fan showed her emotions and raised two peace signs after the postponement of Tuesday's game

Fans outside the Signal Iduna Park check their mobile phones after the match between Borussia Dortmund and AS Monaco was cancelled after the team bus of the Borussia Dortmund football club was damaged in an explosion

Mounted police patrol around the stadium in Dortmund ahead of Tuesday's cancelled match

Emergency vehicles arrived on scene shortly after the explosions and took Bartra to the hospital

Wolves manager Paul Lambert, who lifted the Champions League with Borussia Dortmund in 1997, was inside Signal Iduna Park working as a pundit for BT Sport and said the right decision had been made cancelling the game.

'It looks like the game will be called off and quite right so. It's really uncertain what has happened but you've got to call it off,' he said.

Ex-Dortmund player Steffen Freund, who won the Champions League with Borussia in 1997, said there would be scars.

'When there has been a direct attack on the team bus, then it's not just forgotten by Wednesday,' said the 47-year-old. 'Mentally and psychologically that is hard to absorb, it's a lot to deal with.

European football's governing body UEFA released a statement after the game was postponed.

The statement said: 'This decision was made after a meeting held at the Westfalenstadion between UEFA, representatives of the two clubs and local authorities.'

German Justice Minister Heiko Maas wrote on Twitter following the explosion: 'Shocking news. Our thoughts are with (Borussia Dortmund). You'll never walk alone!'

Germany's interior minister Thomas de Maziere also spoke out after the incident.

He said: 'My thoughts are with the team. Now we have to find out what lay behind this. I hope that tomorrow football will once again take centre stage.'

Germany has seen matches postponed over security concerns before.

In Hannover, in November 2015, Germany's international soccer friendly against the Netherlands was canceled just before kickoff after police feared an explosive device might be detonated at the stadium.

It came days after devices were detonated outside the Stade de France in Paris as France was playing Germany as part of a coordinated attack on the French capital.

Dortmund police said security would be tightened at Wednesday's match, with a major deployment of officers to 'ensure that the game is played safely.'

Separately, security was also being tightened at another major Champions League clash in Germany on Wednesday - between Bayern Munich and Real Madrid.

Germany has been on a high alert since last December's attack in Berlin, when a Tunisian national hijacked a truck and rammed it into a crowd, killing 12 people.