The gunman who shot Russian ambassador Andrey Karlov in the back was a police officer, Turkey's Interior Minister, Suleyman Soylu, has confirmed.

The officer is believed to have used his official identification to enter the art gallery, before opening fire on the ambassador as he gave a speech

It was unclear whether he was on or off duty at the time of the shooting.

A video showed him shouting: "Don't forget Aleppo, don't forget Syria! So long as our brothers are not in safety, you will not taste safety either. Only my dead body will leave here.

"Whoever is involved in this cruelty, one by one, you will pay for it."

He fired at least eight shots, according to an Associated Press photographer in the audience.

The assailant was 'neutralized' during an operation that lasted around 15 minutes by police special forces at the scene, according to the state run Anadolu news agency.

Russian ambassador to Turkey fatally shot at exhibition

Ankara mayor Melih Gokcek told reporters outside the exhibition centre that the "heinous" attack had aimed to disrupt newly-re-established relations between Turkey and Russia.

It came a day before a meeting of Russian, Turkish and Iranian foreign and defense ministers in Moscow to discuss Syria.