The attempted coup has led to a massive crackdown on so-called Gulenists and opponents of the increasingly authoritarian president.
The slain ambassador, Andrei Karlov, was a veteran career diplomat who helped weather rocky ties between Moscow and Ankara.
Karlov, 62, was appointed to Ankara in 2013 at a time when the two countries were pushing to boost trade ties despite deep differences over the Syria conflict.
Russia’s foreign ministry spokeswoman Maria Zakharova described his killing as a “tragic day in the history of our country and our diplomatic service”.
The married father of one spent a large chunk of his career — which stretched back to the Soviet period — working on the volatile Korean peninsula, in both Seoul and Pyongyang.
The Hurriyet Daily News said Karlov was the first ambassador to be assassinated in Turkey, although the British consul was killed in an Istanbul bombing in 2003 and Israel’s consul general was kidnapped and shot dead by leftist militants in 1971.
The shooting came on the eve of a crucial meeting between the Turkish, Russian and Iranian foreign ministers on the Syrian conflict.
At the exact moment of the attack, Turkey’s Foreign Minister Mevlut Cavusoglu was on a plane flying to Moscow for Tuesday’s talks, which he insisted would go ahead.
Moscow and Ankara remain on opposite sides of the conflict — with Ankara backing rebels trying to topple Moscow’s ally President Bashar al-Assad.
