Three suicide bombers who killed 43 people in a gun and bomb attack at Istanbul's main airport this week were Russian, Uzbek and Kyrgyz nationals, a Turkish government official said.
The attack on one of the world's busiest airports was the deadliest in a series of suicide bombings in Turkey this year.
The three bombers opened fire to create panic outside, before two of them got inside the terminal building and blew themselves up.
The third detonated his explosives at the entrance.
A further 239 people were wounded.
The official gave no further details beyond confirming the attackers' nationalities.
Interior Minister Efkan Ala told parliament that evidence continued to point to the so-called Islamic State and that the death toll had risen to 43, of whom 19 were foreigners.
The Yeni Safak newspaper said the Russian bomber was from Dagestan, which borders Chechnya.
Turkey's Hurriyet newspaper named him as Osman Vadinov and said he had come from Raqqa, the heart of Islamic State-controlled territory in Syria.
The Russian interior ministry said it was checking information about Vadinov.
A spokesman for Kyrgyzstan's state security service said it was investigating, while the Uzbek security service had no immediate comment.
The revelation that one of the attackers was a Russian national comes at an awkward time for relations between Ankara and Moscow, strained since Turkey shot down a Russian warplane near the Syrian border last November.
Turkish President Tayyip Erdogan wrote to Russian leader Vladimir Putin this week to express regret over the incident, but officials in Ankara say he stopped short of making the apology Moscow wants before it will lift economic sanctions.
Meanwhile the head of Russia's Security Council sent a telegram to his Turkish counterpart calling for cooperation in fighting terrorism after the bombing, Russian news agencies reported.
Turkish police detained 13 people, four of them foreigners, in a series of raids across Istanbul in connection with Tuesday night's attack.
Broadcaster CNN Turk said they were accused of providing logistical support for the bombings.
Yeni Safak said the organiser of the attack was suspected to be a man called Akhmed Chatayev, of Chechen origin.
Chatayev is identified on a United Nations sanctions list as a leader in IS responsible for training Russian-speaking militants, and is wanted by Russian authorities.
