Turkish sources claim that the three men who carried out the deadly attack on Istanbul’s Ataturk airport on June 28 were all from parts of the former USSR.
One is said to be from Russia’s North Caucasus region and the others from Kyrgyzstan and Uzbekistan.
Turkey believes ISIS was behind the suicide gun and bomb attack that left 44 people dead and some 240 injured.
Meanwhile, Turkish police detained at least 13 suspects in Istanbul and more in Izmir on June 30.
One image on Turkish media purported to show the three men together at the airport moments before the attack, wearing dark jackets and carrying hold alls. Two are wearing caps, one is smiling.
An unnamed Turkish official confirmed for Reuters news agency the dead attackers’ countries of origin after Turkish media reports.
Some agencies named one of the men as Osman Vadinov, said to have crossed into Turkey from the ISIS stronghold of Raqqa in Syria in 2015.
Reports that Osman Vadinov was a Chechen have been denied by an unnamed police source in the North Caucasus, Russia’s Interfax news agency reports.
The organizer of the attack has been named by Turkish media as Akhmed Chatayev, a Chechen believed to have acted as an ISIS recruiter, who is on a US counter-terror sanctions list. His fate was not immediately clear.
ISIS has long recruited members from mainly Muslim parts of the former USSR, with Russian President Vladimir Putin putting the overall number at between 5,000 and 7,000 in October.
However, data published by the Soufan Group security consultants in December suggests the numbers are lower: 2,400 from Russia and 500 apiece from Uzbekistan and Kyrgyzstan.
Turkey’s government has made no official statement on nationalities yet and no-one has said they carried out the attack on June 28.
PM Binali Yildirim said on June 29 that “our thoughts on those responsible for the attack lean towards Islamic State”.
Turkey has carried out raids against suspected ISIS militants after the deadly attack on Istanbul’s Ataturk airport.
At least 13 suspects were detained in the raids in Istanbul, with more in the western coastal city of Izmir.
Turkey believes ISIS was behind June 28 suicide gun and bomb attack that left 42 people dead and more than 230 injured.
More details of the victims have emerged, many of them airport workers.
A Turkish official told AFP: “Earlier today, the police raided 16 locations to detain 13 IS suspects, including three foreign nationals.”
Turkish media said counter-terrorism police had raided several areas of Istanbul – including Pendik, Basaksehir and Sultanbeyli.
Arrests were also reported in Izmir, where at least nine people were detained, accused of financing, recruiting and providing logistical support to ISIS.
Separately, Turkish media reported that security forces had killed two suspected ISIS militants on the Syrian border on June 25. They said one was planning an attack on the capital Ankara or the city of Adana.
No-one has yet said they carried out the airport attack.
The Hurriyet newspaper identified one of the three bombers as a Chechen but there is no official confirmation.
Turkey’s PM Binali Yildirim has said again that “our thoughts on those responsible for the attack lean towards Islamic State”.
President Recep Tayyip Erdogan declared Wednesday a national day of mourning and said the attack should serve as a turning point in the global fight against militant groups.
Detailing the attack, Binali Yildirim said the three men had wanted to pass through the security system but on seeing the controls “took their weapons out of their suitcases and opened fire at random at the security check”.
One attacker detonated his explosives downstairs in the arrivals terminal, Turkish officials said.
The second went upstairs and set off his explosives there while the third waited outside as passengers fled. He then detonated his explosives, causing the most casualties.
A Kalashnikov assault rifle, a handgun and two grenades were found on the bodies, Turkish media said.
In addition to the 42 killed, more than 230 people were injured and dozens remain in critical condition in hospital.
The assault on Ataturk airport – Europe’s third busiest – is the sixth major attack in 2016 targeting either Istanbul or Turkey’s capital, Ankara.
The number of people killed the Istanbul’s Ataturk airport attack has risen to 41 with 239 injured, the Turkish city’s governor says.
Thirteen of those killed in the attack were foreign nationals, he added.
Three attackers arrived in a taxi and began firing at the terminal entrance late on June 28. They blew themselves up after police fired back.
Turkish PM Binali Yildirim said early signs pointed to ISIS.
However, no-one has so far admitted carrying out the attack.
Turkey has declared June 29 a day of national mourning.
Turkish investigators are examining CCTV footage, witness statements and mobile phone video recorded by terrified passengers to try to determine the identity of the attackers.
According to the Dogan news agency, autopsies on the three dead men suggested they may be foreign nationals but this has not been confirmed.
Turkish Health Minister Recep Akdag says that 128 people remain in hospital, including nationals of Saudi Arabia, Afghanistan, Pakistan, Uzbekistan, Ukraine and Switzerland, the Associated Press reports.
Of those, 41 are still in intensive care.
Heavily-armed security personnel were patrolling the airport.
Flights had resumed in the early morning, though with many cancellations and delays.
Turkey’s President Recep Tayyip Erdogan said the attack should serve as a turning point in the global fight against militant groups.
Reports of the attack vary but it appears the attackers opened fire at the entrance where X-ray machines are positioned, sparking an exchange with police. At least two of the attackers ran into the building.
Footage on social media shows one moving through the building as people around him flee. He is shot by police and remains on the ground for about 20 seconds before blowing himself up. All three attackers were killed.
Russian President Vladimir Putin offered his condolences to Turkey in a phone call with President Erdogan, as the pair seek to rebuild ties.
France’s President Francois Hollande has confirmed two French nationals were injured in the attack, but not seriously.
Pope Francis also denounced the “brutal terrorist attack”, saying: “May the Lord convert the hearts of the violent ones and support our efforts toward the path of peace.”
#PrayforTurkey began trending on Twitter after the attack on Istanbul international airport.
At least 36 people have been killed and 147 others injured in a gun and bomb attack in Istanbul’s Ataturk international airport, officials say.
Three attackers began shooting outside and inside the terminal on the evening of June 28 and blew themselves up after police fired at them, officials say.
Turkey’s PM Binali Yildirim said early signs suggested ISIS was behind the attack.
Recent bombings have been linked to either ISIS or Kurdish separatists.
There are X-ray scanners at the entrance to the terminal but security checks for cars are limited.
Pictures from the airport terminal showed bodies covered in sheets, with glass and abandoned luggage littering the building.
President Recep Tayyip Erdogan said the attack should serve as a turning point in the global fight against militant groups.
“The bombs that exploded in Istanbul today could have gone off at any airport in any city around the world,” he said.
The US called the attack “heinous”, saying America remained “steadfast in our support for Turkey”.
German Foreign Minister Frank-Walter Steinmeier said: “We grieve for the victims. We stand by Turkey.”
Speaking several hours after June 28 attack, PM Binali Yildirim said at least 36 people were killed and many wounded, some seriously, with foreigners likely to be among the victims.
The prime minister said the attackers had arrived at the airport in a taxi.
Footage on social media shows one of the attackers running in the departure hall as people around him flee. He is shot by police and remains on the ground for about 20 seconds before blowing himself up. All three attackers were killed.
Justice Minister Bekir Bozdag put the number of injured at 147.
Taxis were used to rush casualties to hospital after the attack. Desperate relatives of those missing later gathered outside a local hospital where many victims were taken. Some expressed anger about the lack of information.
Flights in and out of the airport were suspended after the attack. The US Federal Aviation Administration initially grounded all services between the US and Istanbul but the stoppage was later lifted.
Flights have now resumed at the airport, but information boards showed about one-third had been cancelled, with many delays.