Three Russians suspected of having links to Islamic State have been held in Turkey, a day after a bomb blast in Istanbul.
Almost 60 people have been detained in raids across the country following the suicide attack in a popular square on Tuesday.
Russia's Consulate General in the Turkish city of Antalya has confirmed three Russians suspected of having connections to Islamic State have been arrested.
Police also seized documents and CDs during a search of the premises where the suspects were staying, according to one news agency.
No group has claimed responsibility for the bomb in Sultanahmet Square, which killed 10 German tourists.
Video shows the aftermath of the attack:
Turkish president Recep Tayyip Erdogan said the attack was carried out by a "suicide bomber of Syrian origin".
Officials say he was a Syrian born in 1988.
It is unclear if there was a link between the Russian arrests and the suicide bombing. Turkey is a member of the US-led coalition against IS militants.
It has become a target of the terror group, with two of last year's bombings blamed on them.
One of the blasts, in Ankara, killed more than 100 people.
Journalist in Turkey, Andrew Finkle, says the bomber was not on a terrorist watch list - but the attack has raised questions about border control.