Turkish officials have strong evidence that ISIS leadership was involved in the planning of the Istanbul airport terrorist attack, a senior government source told CNN on Thursday.
Officials believe the men — identified by state media as being from Russia, Uzbekistan and Kyrgyzstan — entered Turkey about a month ago from the ISIS stronghold of Raqqa in Syria, bringing with them the suicide vests and bombs used in the attack, the source said.
The terrorists rented an apartment in the Fatih district of Istanbul, where one of the attackers left behind his passport, the Turkish government source said.
The attack was “extremely well planned with ISIS leadership involved,” the source said.
Turkish police visited the Fatih area and showed neighbors video and photographs of three men they say are believed to have carried out the attack, residents said.
Among the pictures was a screen grab from surveillance video at the airport that shows three men wearing thick jackets and carrying bags, the residents said. One man, the owner of the Bekir Yar Emlak real estate agency, said he told police that the picture showed the men who had lived in his apartment. He said he was shocked to learn they could be the suspects.
Mustafa Elsan, the owner of a garage next to the apartment building, also said he was shown images of the alleged attackers. Elsan said he would see people smoking by the window of that apartment on the first floor of the building, but the curtains were mostly closed.
A female neighbor in the same building, who didn’t want to disclose her name, said there was some smell of chemicals a couple of days ago from the apartment, prompting other neighbors to ask her whether there was a gas leak.
The death toll rose to 44 when a 3-year-old Palestinian boy hurt in the attack died, according to Palestinian officials. The boy’s mother died Wednesday, officials said. And Turkish state news agency Anadolu reported a Turkish man died at a hospital.
While no one has yet claimed responsibility for the airport assault, CNN contributor Michael Weiss, author of “ISIS: Inside the Army of Terror,” said the nationalities revealed Thursday buttress the claim of ISIS involvement.
“One of the toughest battalions in ISIS is called the Uzbek battalion,” he said. “These were the guys who were essentially on the front lines guarding Falluja, the city they just lost in Iraq.”
“Ask anybody inside ISIS or who’s fought ISIS. People from the former Soviet Union tend to be the most battle-hardened and willing to die,” he said.
CNN national security analyst Peter Bergen said the revelation of the Istanbul attackers’ nationalities will serve to “open people’s eyes to the fact that there’s a very substantial Russian, former Soviet Union, presence within ISIS, both in terms of the foot soldiers and the leaders.”
Estimates of Russian fighters involved with ISIS range from 2,000 to 7,000, he said.
Kyrgyzstan’s foreign ministry disputed reports that one of the attackers was from that country.
The ministry said Turkish officials told its representatives that “the identities of the suicide bombers are still being examined.”
Also Thursday, authorities detained 22 people in connection with the attack, according to a Turkish official. Thirteen were taken into custody in Istanbul and nine in the coastal city of Izmir, the official said. Three of those detained were foreign nationals, state media reported.
The terrorists stormed the airport Tuesday night, opening fire and detonating explosives — two of them at the international terminal building, and the third in a parking lot, according to officials. The attack echoed the dual suicide bombings at the main airport in Brussels in March.
Like the attack in Brussels, the terrorists took a taxi to the airport.