
Killer: Turkish police have released this image, which they have identified as the ISIS suicide bomber Nabil Fadli. Fadli killed 11 tourists and injured 14 when he blew himself up in Sultanahmet square in Istanbul

This is the face of the Istanbul suicide bomber who blew himself up in Sultanahmet square near the Blue Mosque and Hagia Sophia, killing 11 tourists and injuring 14.

Nabil Fadli, a 28-year-old ISIS member, had recently entered the country from Syria and registered as a refugee with Turkish immigration authorities in Istanbul just one week before the attack.

CCTV footage released previously showed only the back of Fadli's head as he passed through the immigration office.

Flowers and candles marked the site of the suicide bombing, as Syrians living in the Turkish city gathered to pay their respects to the dead and injured this evening.

Earlier today, a Turkish tour guide revealed how she spotted Fadli 'pulling the pin' in Sultanahmet square, and shouted at the crowd of tourists to run, moments before the massive blast.

Sibel Şatıroğlu, who was wounded in the explosion, had been guiding a group of some 25 people when she saw Fadli before he detonated the bomb which killed 10 German tourists and one Peruvian, and injured 14, one who later died in hospital.

'I was with a group of 20-25 people near the Obelisk. I heard a trigger sound. I realised it wasn't a normal sound and I looked around me,' Ms Satiroglu, who suffered a leg wound and hearing loss in the blast, told police according to WorldBulletin.

'Amongst our group I noticed someone who appeared to be Turkish looking in our German group. He had a cleanshave face, with a small beard. I saw him pull the pin trigger, and I screamed for everyone to run. We started running as the bomb exploded'.

Witnesses say that there could have been many more deaths, had it not been for Ms Şatıroğl shouting 'Lauft weg!'(run away) to the large group of German tourists standing in the square.

Fadli has been confirmed as carrying out the blast in the name of ISIS, and had registered with Turkish immigration authorities but was not on any list of known militant suspects, Turkey's interior minister said on Wednesday.

Asked about a report in the Turkish media that the bomber had registered at an immigration office in Istanbul a week ago, Interior Minister Efkan Ala confirmed that the man's fingerprints were on record with the Turkish authorities.

Scroll down for video

CCTV: ISIS member Nabil Fadli, a 28-year-old Saudi Arabian-born Syrian national, was caught on camera while registering at an immigration office in Istanbul last Tuesday

Bomber: Turkish authorities said Fadli had recently entered the country from Syria, and was identified from bodyparts found at the scene

'Your assessment that his fingerprints were taken and there is a record of him is correct. But he was not on the wanted individuals list. And neither is he on the target individuals list sent to us by other countries,' Ala told a joint news conference with his German counterpart Thomas de Maiziere.

Meanwhile, Turkish authorities have detained three Russian men with links to ISIS in connection with the massive explosion in the Sultanahmet neighbourhood, an area home to some of Istanbul's most popular tourist attractions.

Hero: Sibel Şatıroğlu saw the attacked pulling the pin before he detonated the bomb in Istanbul which killed ten people

At least 10 German travellers and one man from Peru were killed in the blast. Six Germans, one Norwegian and a Peruvian were also wounded in the blast, with one of the German nationals later dying in hospital.

Russia's Consulate General in the Mediterranean city of Antalya has today confirmed that three Russians had been detained over suspected connection to ISIS.

Police also seized documents and CDs during a search of the premises where the suspects were staying, Turkey's Dogan News Agency said. It was not immediately clear when the detentions occurred.

A picture circulated online by Turkish media showed a giant fireball erupting next to an Egyptian obelisk where tourists had gathered, however the image has not been independently verified.

Witnesses said the blast shook buildings and could be heard across the city, while images showed corpses and body parts strewn across a square near iconic sites including the Blue Mosque and the Hagia Sophia museum.

Chancellor Angela Merkel vowed to strike back against the 'cruel and inhuman face' of terrorism, after it emerged that German nationals were among those killed.

Travellers were warned to stay away from tourist sites and crowds in the city as other European countries including Britain worked to establish if any of their citizens had been involved in the blast.

Turkish president Recep Tayyip Erdogan said both Turks and foreigners were among the dead, adding that the attack was carried out by a 'suicide bomber of Syrian origin'.

Deputy Prime Minister Numan Kurtulmus added that the bomber was a 28-year-old Syrian national, while two senior Turkish security officials said there was a high probability ISIS were responsible.

The blast struck at 8.20am GMT around the Obelisk of Theodosius, a monument from ancient Egypt which was re-erected by the Roman Emperor Theodosius and is one of the city's most eye-catching monuments.

Police cordoned off the area to shocked passers-by and tourists and the nearby tram service has been halted amid fears of a second blast.

A German tourist named Caroline said: 'The explosion was so loud, the ground shook. There was a very heavy smell that burned my nose.

Destruction: This picture purportedly shows the moment the Syrian suicide bomber blew himself up neat to an Egyptian obelisk in the heart of Istanbul's tourism district, killing 11 tourists and injuring 14 others

Terror in Turkey: Eleven people have died and 14 others were injured when an explosion from a Syrian suicide bomber ripped through a tourism district in the centre of Istanbul near the Obelisk of Theodosius, a monument from ancient Egypt

Remembrance: Syrian mourners gather on Wednesday night at the site of the attack, after a 28-year-old ISIS member blew himself up

Loss: Syrians living in the Turkish city gathered on Wednesday to mourn the deaths of 11 tourists - 10 Germans and one Peruvian national

Tragedy: Mourners gathered with candles and flowers, after it was revealed that the bomber had registered as a refugee just a week before

Honour: A Syrian man living in Istanbul lights a candle at the site of the blast, whick killed 11, in Sultanahmet square in the Turkish city

Respect: Flowers and candles lie at the foot of the obelisk in Sultanahmet square in Istanbul, after an ISIS suicide bomber targeted tourists

'I started running away with my daughter. We went into a nearby building and stayed there for half an hour. It was really scary.'

Erdem Koroglu, who was working at a nearby office, told NTV television he saw several people lying on the ground.

'It was difficult to say who was alive or dead,' he said. 'Buildings rattled from the force of the explosion.'

Another witness said: 'The explosion was very loud. We shook a lot. We ran out and saw body parts.'

Turkey's Dogan news agency reported at the time that at least six Germans, one Norwegian and a Peruvian were among the wounded, while Seoul's Foreign Ministry said one South Korean had a finger injury.

One of the injured tourists was a Norwegian tourist who says his knee was pierced by shrapnel from the explosion.

Jostein Nielsen, a 59-year-old Salvation Army officer, told Norway's TV2 that he and his wife were sightseeing in the Turkish city when the bomb went off.

'I first heard a bang that I think is what detonated the bomb. After that came the real bang. I felt that my knee stopped working. There were human remains all over the place,' Nielsen said.

Nielsen is currently in hospital with his knee heavily bandaged. He revealed that the doctors believed that he will be able to walk again.

Arrests: Turkish authorities detained three Russian nationals suspected of links with ISIS following a suicide bomb attack in Istanbul that killed 11 tourists and injured 14 people

Detained: Police also seized documents and CDs during a search of the premises where the three Russian suspects were staying

Terror attack: Bodies litter a square after an explosion ripped through the Sultanahmet district of Istanbul, the city's main tourist hub

'It was a great shock. One does not think that such things will happen when you are sightseeing,' his uninjured wife Magna Vaaje Nielsen said.

'I condemn the terror incident in Istanbul assessed to be an attack by a suicide bomber with Syrian origin,' Erdogan told a lunch for Turkish ambassadors in Ankara in a speech broadcast live on television.

'Unfortunately we have 10 dead including foreigners and Turkish nationals,' Erdogan told a lunch for Turkish ambassadors in Ankara, in a speech broadcast live on television.

'This incident has once again showed that as a nation we should act as one heart, one body in the fight against terror. Turkey's determined and principled stance in the fight against terrorism will continue to the end.'

Omer Celik, the spokesman for Prime Minister Ahmet Davutoglu's ruling party, issued a statement condemning what he called 'a heinous attack'.

Horror: The blast rocked the Sultanahmet neighbourhood in central Istanbul which is visited by tens of thousands of tourists every day

Gruesome: A dead body lies on the ground after an explosion near by Blue Mosque in the Sultanahmet district of central Istanbul

Fear: Police cordoned off the area to shocked passers-by and tourists and the nearby tram service was halted amid fears of a second blast

Emergency: Paramedics carry a dead body after an explosion near the Blue Mosque in the Sultanahmet district of central Istanbul, Turkey

Tourism: Turkish police officers search the area after an explosion near the famous Blue Mosque in the Sultanahmet district of Istanbul

Chancellor Angela Merkel said on Tuesday that members of a German tour group were among the likely casualties and that German officials were working with their Turkish counterparts to determine the identities of the victims and offer assistance to their loved ones.

She said: 'We don't have all the information yet... but we fear that German citizens could be and probably are also among the victims and injured.'

Merkel said the latest attack would deepen German resolve to combat international terrorism.

'Today it hit Istanbul, it has hit Paris, it hit Tunisia, it had already hit Ankara,' she said at a press conference following talks with visiting Algerian Prime Minister Abdelmalek Sellal.

'International terrorism once again showed its cruel and inhuman face and along with the sorrow that we of course feel, it once again shows the necessity to act decisively against terrorism and ultimately overcome these atrocities.'

Foreign Minister Frank-Walter Steinmeier, whose ministry set up a crisis team in the wake of the attacks, also condemned the blast as a 'barbaric' act of terrorism.

'We must assume that Germans were hurt and we cannot exclude that Germans were among the dead,' he said.

Germany warned its nationals to avoid tourist sites in Istanbul, a city of about 14 million people that has been hit several times in the past by deadly attacks.

On high alert: Police sealed off the area, barring people from approaching the scene in case of a second blast

Terror: Turkey is on edge after series of deadly attacks by ISIS including a double suicide bombing in Ankara in October that left 103 dead

Aftermath: Turkish police officers search the area after an explosion near the Blue Mosque in the Sultanahmet district of central Istanbul

Probe: Police forensic experts work on the scene of the explosion in central Istanbul which killed at least 11 people and injured 14 others

Protection: A member of the Turkish SWAT stands guard by a building after the explosion which killed 11 and injured 14 others

'Travellers in Istanbul are strongly urged to avoid for now large groups of people in public places as well as tourist attractions' and to stay informed via official travel advisories and the media, the foreign ministry said.

The ministry warned of possible 'political tensions as well as violent clashes and terrorist attacks across the country', adding that tourists should avoid large demonstrations.

British Foreign Secretary Philip Hammond announced the breaking news to MPs during Foreign Office questions, promising to keep them updated if any news about UK nationals emerged.

Opening the Commons session, he said: 'I wonder if I might just take a few seconds to update the House on the breaking news coming in from Istanbul where an explosion has occurred in the Sultanahmet area, killing at least 10 people, with many more injured.

'This is a tourist area of the city and we already know that some tourists are involved in this incident.

Concern: Police move people on as they secure an area at the historic Sultanahmet district of Istanbul amid fears of a second explosion

Tourism terror: The blast occurred next to the Obelisk of Theodosius, a monument from ancient Egypt, near world-famous sites including the Blue Mosque, Topkapi Palace and the Hagia Sophia museum

'We are at the moment seeking to verify whether any British nationals are involved and if we get any news on that during the course of the next hour I will update the House accordingly.

'In the meantime, I offer my sympathies to the victims and their families and everyone else affected by the attack.'

A spokeswoman for the Norwegian Foreign Ministry in Oslo said the office worked with the embassy in Turkey to check media reports of Norwegian citizens among the wounded.

Turkey is on alert after 103 people were killed on October 10 when two suicide bombers blew themselves up in a crowd of peace activists in Ankara, the bloodiest attack in the country's modern history.

That attack was blamed on ISIS, as were two other deadly bombings in the country's Kurdish-dominated southeast earlier in the year.

Turkish authorities have in recent weeks detained several suspected ISIS members, with officials saying they were planning attacks in Istanbul.

The country is also dealing with more than two million Syrian refugees and a wave of migrants from Syria and other countries pouring across Turkey to Europe.

Security: Police secure the area after an explosion near the Ottoman-era Sultanahmet mosque, known as the Blue mosque in Istanbul

Busy: Sultanahmet neighbourhood is home to the city's biggest concentration of monuments and is visited by thousands of tourists a day

Watch: Police cordoned off the area to shocked passers-by and tourists and a nearby tram service was halted amid fears of a second blast

But Turkey is also waging an all-out assault on the outlawed Kurdistan Workers' Party (PKK) which has staged dozens of deadly attacks against members of the security forces in the southeast.

The PKK launched an insurgency against the Turkish state in 1984, initially fighting for Kurdish independence although now more for greater autonomy and rights for the country's largest ethnic minority.

The conflict, which has left tens of thousands of people dead, looked like it could be nearing a resolution until an uneasy truce was shattered in July.

A Kurdish splinter group, the Freedom Falcons of Kurdistan (TAK), claimed a mortar attack on Istanbul's second international airport on December 23 which killed a female cleaner and damaged several planes.