Akhmed Chatayev was identified by the pro-government Yeni Safak newspaper as the organizer of the coordinated assault, which killed 44 and wounded more than 200 others at Turkey’s Ataturk Airport. Turkish officials did not immediately confirm he was involved in the attack, and it was unclear if Chatayev was one of the airport bombers, in custody or on the run.

Authorities said all information suggested the airport assault was the work of ISIS and, despite no claim of responsibility for the attack, Chatayev’s involvement would show an ISIS link.

Chatayev had been designated in October as a terrorist by both the U.S. Treasury Department and UN Security Council for supporting ISIS. The Treasury report identified Chatayev as a member of “a group of militants that was planning attacks against U.S. and Turkish facilities” and the UN report said Chatayev “directly commands 130 militants” and was the “organizer and mastermind of planned” terror acts against Russian interests abroad.