Jane Onyanga-Omara

USA TODAY

The three suicide bombers who attacked Istanbul's main airport, killing 44 people, were from Russia, Uzbekistan and Kyrgyzstan, a senior Turkish official said Thursday.

The statement came as counter-terror teams launched 16 simultaneous raids in Istanbul, Reuters reported, quoting two unidentified officials. Turkish police said they detained 13 people, including three foreign nationals, in connection with the attack, local media reported.

The Karsi newspaper, quoting police sources, said the trio was part of a seven-person cell who entered Turkey on May 25. The assailants raised the suspicion of airport security on the day of the attack because they showed up in winter jackets on a summer day, several media outlets reported.

Turkish officials, meanwhile, raised the death toll to 44, including 19 foreign nationals, with 230 people injured. Among those wounded, 94 remained in the hospital, the Istanbul governor’s office reported.

The private Dogan news agency said the Russian attacker entered the country one month ago and left his passport in a house the men rented in the neighborhood of Fatih.

The senior Turkish official, who spoke on condition of anonymity in line with government regulations, did not name the attackers, the Associated Press reported. He also would not confirm Turkish media reports that the Russian national was from the restive Daghestan region.

Authorities believe the Islamic State is behind the attack, although the terrorist group has not officially claimed responsibility.

Turkish police have reportedly identified Ahmet Chatayev, a Chechen terrorist, as the mastermind of the attack, according to the Turkish newspaper Yeni Safak. He is described as working for the founder of the Chechen Islamic Emirates and joined the Islamic State in 2013.

The newspaper, quoting unidentified intelligence sources, said the terrorist prepared the attack in a rental house in an Istanbul neighborhood near a shopping mall. The newspaper said surveillance video shows the terrorists taking a taxi from the shopping mall to the airport on the day of the attack.

Earlier Thursday, nine suspects linked to the group, also known as ISIL or ISIS, were also arrested in large-scale police raids in the coastal city of Izmir, Anadolu reported. Police said they found three hunting rifles and documents related to the extremist group during the searches, according to the agency.

Turkish authorities declared a day of national mourning after the attack, carried out by three suicide bombers late Tuesday.

Officials: Early airport security helped disrupt Istanbul attack

The attackers arrived together at the lower-level arrivals hall; one went inside, opened fire and then detonated his explosives, an Interior Ministry official and another official told the Associated Press. During the chaos, the second attacker went upstairs to departures and blew himself up.

The third man waited outside during the whole episode and detonated his explosives last as people flooded out of the airport, officials said. The officials spoke on condition of anonymity because they were not authorized to speak publicly about the investigation.

President Obama phoned Turkish President Recep Tayyip Erdogan on Wednesday to express his condolences. He also pledged to dismantle “organizations of hate,” saying the attack in Istanbul shows how little these “vicious organizations” have to offer.

Contributing: Victor Kotsev and Onur Erem

Routine night of Istanbul airport duty, then horror and death