Russia's ambassador to Turkey was shot and killed in Ankara yesterday, the Russian Foreign Ministry said, with video footage showing the attacker, said to be an off-duty police officer, shouting Islamist slogans and denouncing the situation in Aleppo.

Russia is considering the assassination of Andrey Karlov, a veteran diplomat, as an "act of terrorism," Foreign Ministry spokesperson Maria Zakharova said on her Facebook page. Turkey's Foreign Ministry also spoke of terrorism in its condemnation.

"We are in contact with Turkish officials who have received confirmation that there will be a thorough, multilateral investigation," Zakharova said in comments carried by Russia’s state news agency Tass.

Turkish President Recep Tayyip Erdogan and his Russian counterpart Vladimir Putin spoke by telephone about the assassination, the state-run Anadolu news agency reported, citing a spokesperson.

The shooter, wearing a dark suit and tie, shot the ambassador in the back and proceeded to wave his gun as he paced the room of the art gallery where the incident took place.

While walking back and forth he shouted "Allahu Akbar" several times, along with an Arabic saying attributed to the companions of the Prophet Muhammad, popularised in violent Islamist circles as a battle hymn, including by Syrian hardline rebels in their videos.

Gunman cries, 'Do not forget Aleppo'

"We are those who swore allegiance to Muhammad and to the jihad," the shooter screamed before changing to Turkish and focusing on Syria, saying "do not forget Aleppo, do not forget Syria," and vowing those responsible for "cruelty" in the neighbouring country would pay the price.

Turkish newspaper Hurriyet and other local media reported that the gunman was a 22-year-old off-duty police officer and may have used his police identification to enter the premises.

The mayor of Ankara, Melik Gokcek, also indicated on Twitter that the attacker was a member of the police force.

Turkish state news agency Anadolu said the attacker was "neutralised" by the security forces, without elaborating. Reports indicated he was killed.

Russia and Turkey, which support opposite sides in the Syrian civil war, have managed to patch up rocky relations in recent months, after Turkish forces shot down a Russian warplane on the Turkish-Syrian border last year.

An official with Erdogan's ruling Justice and Development Party (AKP) in Turkey indicated the attack may be an attempt to disrupt the newly-formed ties between the governments.

Russia and Turkey in recent days have been working together to evacuate civilians and militants from a rebel-held enclave in Aleppo amid a major offensive by Syrian state forces to take control of the city. Russia is the Syrian government's main military backer.

Turkish Foreign Minister Mevlut Cavusoglu was set to attend meetings in Moscow today about the war in Syria, where Russia has been carrying out air strikes in support of the government while Turkey backs the armed opposition. The talks will go ahead, Anadolu said.

The United States ambassador to the United Nations, Samantha Power, condemned the "savage attack."

Karlov was a veteran Russian diplomat. He was married and had a son, according to the website of the Russian embassy in Ankara.

- dpa