The Russian ambassador to Turkey has been shot dead by a police officer who shouted “Don’t forget Aleppo” as he pulled the trigger.

The chilling attack on Monday evening, which was captured on video, appeared to be a backlash against Russian military involvement in the Syrian civil war.

Andrei Karlov was attacked at the opening of an art exhibition in Ankara by a man believed to be an off-duty Turkish police officer. Karlov was several minutes into a speech when he was shot. Footage of the attack showed a man dressed in a suit and tie standing calmly behind the ambassador. He then pulled out a gun, shouted “Allahu Akbar” and fired at least eight shots.