Russian ambassador Andrey Karlov was attacked by unidentified gunmen late Monday in Ankara.
Karlov was shot with a gun while making a speech at a painting exhibition in the Turkish capital, the Russian embassy said, adding it believed that it was a radical Islamist attack.
The attack comes a day before Turkish Foreign Minister Mevlüt Cavusoglu heads to Moscow for talks on Syria with his Russian and Iranian counterparts.
Private broadcaster CNN Turk said Karlov was in a critical state.
Meanwhile, private broadcaster NTV said three other persons were also injured in the attack.
CNN Turk said the attacker might be still inside the building and that Karlov had not yet been sent to hospital.
--IANS
mr/nir