FREE now and never miss the top politics stories again. SUBSCRIBE Invalid email Sign up fornow and never miss the top politics stories again. We will use your email address only for sending you newsletters. Please see our Privacy Notice for details of your data protection rights.

Prosecutors announced two suspects with Islamist terror links have become the focus of their enquiries folowing the bomb blast yesterday. A statement from the federal public prosecutor's office claimed investigators had searched the apartments of two suspects from Germany's Islamist scene and decided to detain one of them. Officials failed to confirm where the suspect was detained but added that a decision would be made on whether to seek a judicial arrest warrant against him.

GETTY One player was injured in the blast on the Borussia Dortmund bus

The prosecutor added metal strips had been used in the explosive devices activated in the attack, which injured one player, with one of the 'spikes' being found drilled into the headrest of one of the seats on the bus. Officials confirmed the attack is being treated as having a "terrorist background" but authorities said: "The precise motive for the attack is unclear at present." But lead prosecutor Frauke Koehler confirmed three letters containing the same text were found near the site of the blasts, and indicated the attacker had links to so-called Islamic State.

REUTERS The match has been postponed until tonight

Chancellor Angela Merkel condemned the "appalling" attack on Wednesday, with her spokesman saying: "The chancellor was last night, like people in Dortmund, like millions everywhere, appalled by the attack on the BVB team bus. "One can only be relieved that the consequences were not worse." And he added that investigators were doing everything in their power to track down the perpetrator, or perpetrators. Ralf Jaeger, interior minister in the state of North Rhine-Westphalia which includes Dortmund, said the investigation was looking "in all directions", and it was unclear if one or several attackers were involved.

Borussia Dortmund attack in pictures Tue, April 11, 2017 A football player has been injured after three bombs exploded near Borussia Dortmund's team bus ahead of a Champions League match against Monaco Play slideshow EPA 1 of 23 A view on the damaged windows of the Borussia Dortmund's team bus after it was hit by three explosions in Dortmund, Germany

ANTIFA, the left wing anti-Nazi group, reportedly claimed responsibility on the internet on Wednesday morning according to Focus online magazine. In a post online, it says the bus was targetted because the Dortmund team had not done enough to fight racism, right-wing populism and neo-Nazism. And they added the attack was a "symbol of the politics" of the club. Borussia Dortmund has been recently plagued with violent, far-right hooliganism - with a recent crackdown leading to stadium bans, resulting in death threats in February for one manager. But the state prosecutor claimed officials had reason to believe this letter was not authentic. Germany's Sueddeutsche Zeitung newspaper suggested another three letters, which were found near the scene, claimed responsibility for Islamic State. It said a letter left near the scene of the attack on Tuesday claimed it was in retaliation for German military reconnaissance missions against Islamic State in Syria.

REUTERS The Federal Public Prosecutor said in a statement it had taken over the investigation

REUTERS Player Marc Bartra was injured in the blast

Public prosecutor Sandra Lucke confirmed one note claiming responsibility for the incident was found near the site of the explosions. She said: "The background [of the attack] is being investigated thoroughly. The investigations are based on a suspicion of [attempted] homicide. "A claim of responsibility was found near the crime scene. The authenticity is currently being attested. "I can't tell you more about the content because of ongoing investigations. We are investigating in all directions."

REUTERS The blast shattered the bus windows

After the bang, we all ducked in the bus and those who could threw themselves to the ground. We did not know had happened. Goalkeeper Roman Burki

The Federal Public Prosecutor said in a statement it had taken over the investigation and would hold a news conference at midday today. Polcie also confirmed an explosive-like item was found at the team's hotel after the blasts but it did not ignite. Player Marc Bartra underwent an operation after breaking a bone in his wrist, but no other players were hurt in the blast. Goalkeeper Roman Burki, who was sitting at the back of the team bus alongside Bartra, recalled how events unfolded.

REUTERS Dortmund player Marc Bartra underwent an operation after breaking a bone in his wrist

He said: "We left the hotel at 7:15pm and went down the street. The bus turned down the main street, and there was a giant explosion. "I was sitting in the back row next to Marc Bartra, who was hit by fragments of the broken glass. "After the bang, we all ducked in the bus and those who could threw themselves to the ground. We did not know had happened. "The police were quick on the scene, and we were safe. We're all shocked - nobody thought of a football match in this moment."

REUTERS The Champions League fixture was postponed after the attack

Tuesday's Champions League quarter-final first leg has now been postponed, and has been rescheduled for Wednesday, with a 5.45pm kick off. Chief executive Hans-Joachim Watzke said: "In such a crisis situation, all of Borussia will pull together. "The team and coaches were shocked. Now we must channel it in some way."

GETTY There have been a number of previous attacks involving football teams

GETTY The bomb was believed to be in a nearby hedge