Attention focused Friday on whether a Chechen extremist known to be a top lieutenant in the Islamic State group was involved in the suicide attacks that killed 44 people at Istanbul's Ataturk Airport.
U.S. Rep. Michael McCaul, chairman of the House Committee on Homeland Security, told CNN that Akhmed Chatayev directed Tuesday night's attack at one of the world's busiest airports. The CIA and White House declined to comment on McCaul's assertion and officials said the investigation of the bombing is still ongoing. McCaul could not be reached for further comment.
Turkish officials also were not able to confirm Chatayev's role. The Sabah newspaper, which is close to the government, said police had launched a manhunt for him.
McCaul said Chatayev's whereabouts are unknown. The 35-year-old one-armed militant, who fought in Chechnya against Russian forces and their local allies in the early 2000s before fleeing to the West, was put on the U.S. list of suspected terrorists in 2015. That same year, he resurfaced in an IS video as the commander of the group's Chechen battalion in Syria.
Although no one has claimed responsibility for the airport attack, the Islamic State group is suspected, and Turkish President Recep Tayyip Erdogan repeated Friday that IS was "most probably" behind it. The group has boasted of having cells in Turkey and other countries.
"They have no connection to Islam. Their place is in hell," Erdogan said, speaking in Istanbul following Friday prayers. "These people were innocent; they were children, women, elderly ... They embarked on a journey unaware, and came face to face with death."
The state-run Anadolu Agency reported Friday that the Bakirkoy Public Prosecutor's office had established the identity of two of the airport attackers, Rakim Bulgarov and Vadim Osmanov, and was trying to identify the third. Other media reports have given different versions of Osmanov's name.
Anadolu said Osmanov's identity was determined through a photocopy of his passport, which he submitted to a realtor in order to rent a house in Istanbul's Fatih district. Police were also trying to access information on a destroyed computer found in a trash bin near the house.
The Anadolu report did not provide the nationalities of the suspects. On Thursday, a Turkish official said the three attackers were from Russia, Kyrgyzstan and Uzbekistan.
Thirteen people suspected of possible links to the attack were detained in raids Thursday in three Istanbul neighborhoods, officials said. The Haber Turk newspaper said 11 more suspects — all foreigners — were detained in a separate raid early Friday. A government official could not immediately confirm the report.
The IS group, which has used the porous border with Turkey to establish itself in neighboring Syria and Iraq, has repeatedly threatened Turkey. In turn, Turkey has blamed IS for several major bombings in the past year in Ankara and Istanbul.
Turkey, a NATO member and key partner in the U.S.-led coalition against the Islamic State group, also faces security threats from Kurdish rebels who are demanding greater autonomy in Turkey's southeast region and from ultra-left radicals. Kurdish rebels have carried out numerous car bomb attacks in the past year, including an attack Feb. 17 in Ankara that killed 39 people, and another devastating bombing in the capital in March.
An official said Friday that security forces have killed the mastermind of the Feb. 17 attack.
Mehmet Sirin Kaya was killed in the town of Lice in the mainly Kurdish province of Diyarbakir, the official said. He spoke on condition of anonymity in line with government regulations.
The attack against military personnel was claimed by an offshoot of the Kurdistan Worker's Party, or PKK, which Turkey considers a terrorist organization.