Andrey Karlov, Russian ambassador to Turkey has been shot dead while visiting an art exhibition in Ankara.

The Russian official was shot in the back multiple times as he gave a speech at the art gallery by an off-duty police officer who shouted “Don’t forget Aleppo” and “Allahu Akbar” as he opened fire.

The attacker, 22-year-old Mevlüt Mert Altıntaş, was in formal black tie attire and was captured by the press standing, alone behind the ambassador while he was addressing the guests.

“He took out his gun and shot the ambassador from behind. We saw him lying on the floor and then we ran out,” a witness, who asked not to be identified, told Reuters. “People took refuge in adjoining rooms as the shooting continued.”

“We die in Aleppo, you die here. You will not taste security until our towns are secure. Do not forget about Syria and Aleppo. Whoever is part of it will get their punishment,” the assassin reportedly yelled before he got killed by security forces.

According to a cameraman covering the event, the exchange of fire went on for several minutes before the gunman was shot.

Mobile phone videos and snapshots that went viral show the ambassador lying on the floor among four other bodies of people who attended the art exhibition.

Meanwhile, Russia has asked citizens to ignore Turkish announcements over the shooting and wait for Kremlin’s official stance.

Vladimir Putin’s first statement, vowing to wage war on terror has spurred fears for more turmoil in the area as Russia and Turkey, have both intervened militarily in Syria and are on opposite sides of the conflict.

Russia’s support towards Syrian President Bashar al-Assad’s powers has enraged Turkey that has allied with rebel powers seeking to overturn Assad.

The attacker’s act has been linked to the failed July coup in Turkey and the purging of police forces that were said to stand beside US-based Muslim cleric Fethullah Gulen. This unofficial, but popular allegation might cause further tensions between Turkey and the United States as Turkish government pushes for Gulen’s expedition.

Erdogan claims Gulen created a “parallel network” in the police, military, judiciary and civil service aimed at overthrowing the state.

Moreover, gunshots near the US. Embassy in Ankara and the State Department have also been reported and Americans have been warned to avoid the area.

The shooting incident raises concerns about the Turkish police force currently being purged after