Syria has handed over to Turkey 22 people suspected of involvement in recent deadly bomb attacks in Istanbul.
More than 60 people died in the attacks
The suspects reportedly fled Turkey after the mid-November bombings, the country's Anatolia news agency reports.
More than 60 people died in four attacks which targeted two synagogues, the British consulate and a British bank within the space of five days.
A BBC correspondent in Istanbul says this is the hardest evidence so far of an international aspect to the attacks.
In Turkey itself, officials have identified the third of four bombers who carried out the attacks.
Istanbul Governor Moammer Guler named the bomber who targeted the HSBC bank as Ilyas Kuncak, who was in his forties and came from the capital, Ankara.
Husband and wife
The Governor of the Turkish border province of Hatai said the Syrian authorities handed over the suspects to Turkish officials.
A Turkish police statement said a husband and wife believed to be connected to bombing prime suspect Azat Ekinci were among the group.
So far, 21 people have been arrested
Mr Ekinci was not among the suspects transferred to Turkey.
Twenty-one people have so far been arrested in connection with the attacks and 16 more are being interrogated.
The expulsions were the latest sign of progress in the investigation into the bombings.
On Saturday, Turkey laid its first charge against a suspect in connection with one of the synagogue bombings.
Police said the man was captured trying to cross into Iran.
He was charged with attempting to overthrow Turkey's "constitutional order by force" - a crime which has been used in past terror trials and carries a punishment of life imprisonment.
The suspect is believed to have gathered intelligence on Istanbul's Beth Israel synagogue and ordered the bombing on 15 November.
Turkish authorities have named 29-year-old Mesut Cabuk and Gokhan Elaltuntas, 22, as the suicide bombers who blew up Beth Israel and Neve Shalom synagogues respectively.