Turkey has asked Moscow to extradite Mihrac Ural, a terrorist responsible for deadly attacks five years ago who was seen among participants at the Syria congress in Sochi, Russia early this week.
"We immediately reacted to this terrorist's participation there and demanded an explanation from Russia," Foreign Minister Mevlut Cavusoglu told reporters on Thursday.
“We want this person's immediate detention and extradition to Turkey.”
He said Ural is being sought by an Interpol red notice.
During a phone conversation on Wednesday, Turkish President Recep Tayyip Erdogan voiced "discomfort" to his Russian counterpart Vladimir Putin about the terrorist’s presence in Sochi, as he was not included on the list of invited delegates given to Turkey, said Cavusoglu.
The guarantor countries in the Syrian peace process -- Russia, Iran and Turkey -- had agreed to hold talks in Sochi on Monday and Tuesday.
Turkey had repeatedly insisted that while all sectors of Syrian society would be represented there, no terrorists or terrorist groups would be allowed.
"Actually, the name of this terrorist was not on the list that Russia gave us. If it had been, we would have objected beforehand," said Cavusoglu.
He said Ural entered Russia with "fake documents."
"We were uncomfortable with this," he added, saying that Putin himself will care about the issue.
Turkey blames Ural for a spate of attacks in May 2013 in the town of Reyhanli in Turkey’s southern Hatay province that left 52 people dead.
Ural is the leader of the THKP-C, a pro-Syrian regime militia.