Seventeen suspects are due to appear in a Turkish court, state media say, in connection with last week's suicide bombing attack on Istanbul's main airport that killed 45 people and wounded hundreds.
The suspects, 11 of them foreigners, were expected in court on Monday after being questioned by police, state-run Anadolu Agency reported.
The court will decide whether to jail them pending trial or release them, it said.
Thirteen other suspects, three of them foreigners, were remanded by a court on Sunday pending trial.
The triple suicide bombing at Istanbul Ataturk Airport on Tuesday, which officials believe to have been carried out by Islamic State, was the deadliest in a series of suicide bombings this year in Turkey.
Three bombers opened fire to create panic outside the airport before two of them got inside and blew themselves up. The third militant detonated his explosives outside at the entrance to the international arrivals terminal.
Russian nationals have been identified as two of the suspected bombers, Anadolu reported last week.
Turkish officials have not commented on the report, although one official had said the attackers were Russian, Uzbek and Kyrgyz nationals.
The pro-government Yeni Safak newspaper has said the organiser of the attack was suspected to be a Chechen double-amputee called Akhmed Chatayev.
He is identified on a United Nations sanctions list as a leader in Islamic State responsible for training Russian-speaking militants.
Both Turkey and Russia have said that they need to cooperate more to combat Islamic State, highlighting the threat from Russian-speaking militants.