The Russian ambassador to Turkey was tonight shot dead by an off-duty Turkish police officer at an art gallery in Ankara in an apparent ‘revenge’ attack at the conflict in Syria.

Ambassador Andrei Karlov, 62, was repeatedly shot in the back at close range by a gunman shouting: ‘Allahu Akbar (God is Great). We die in Aleppo, you die here!’ He also screamed: ‘Only death will take me out of here.’

The gunman has been identified as Mevlüt Mert Altintas, 22, a member of Ankara’s police riot squad, fired into the air before taking aim at the ambassador. Three others were also injured, according to local media.

Shocking footage of the attack shows Altintas, dressed in a suit and tie, pacing the gallery while brandishing a gun in one hand. The killer was shot dead after a 15-minute standoff with special forces police.

Putin has declared the assassination a ‘provocation’ while a Kremlin spokeswoman called it a ‘terror attack’. Turkey’s foreign minister tonight said the two countries would work together to investigate the killing.

The assassination follows days of protests in Turkey over Russia’s role in Syria and comes just one day before the Russians are due to host Turkey and Iran’s foreign ministers for talks on the evacuation of civilians from Aleppo.