Russian officials investigating the assassination of their ambassador to Turkey have vowed that the killing would not disrupt efforts to repair the two countries' relationship.
Inquiries are focusing on whether the man who shot Andrei Karlov at a photo exhibition launch in the Turkish capital Ankara was a "lone wolf" gunman, or part of a wider conspiracy.
In a separate attack, a man with a shotgun was detained after he fired into the air outside the US Embassy in Ankara. No-one was hurt in that incident.
Ankara and Moscow back opposing sides in the Syrian civil war.
Mr Karlov was shot dead on Monday by a Turkish policeman who shouted slogans about Aleppo, a Syrian city where Russian bombardments have targeted rebel factions. The gunman, identified as Mevlut Mert Altintas, was later killed in a shoot-out with police.
Authorities identified him as a 22-year-old member of Ankara's riot police squad, but did not disclose any motive for the attack.
On Tuesday, the foreign ministers of Russia and Turkey attended a previously scheduled meeting in Moscow, where they said they were committed to advancing peace efforts in Syria.
Turkish foreign minister Mevlut Cavusoglu said Turkey and Russia would work together to determine who was behind the "heinous terror attack" against Mr Karlov, who was killed in front of a stunned audience while making remarks at a photo exhibition in Ankara.