Russian ambassador, Andrei Karlov was shot dead in Ankara by a gunman, while several other people were seriously injured.
The BBC reports that the attack came a day after protests in Turkey over Russia’s military intervention in Syria. It says the attack was apparently made in protest at Russia’s involvement in the Syrian conflict.
According to Russian TV, the ambassador had been attending an exhibition called “Russia as seen by Turks”.
It was reported that Police later “neutralised” the gunman, but his details was not given at the time of compiling this report.
Mr Karlov was rushed to hospital, reports said, but his death was later confirmed by the Russian foreign ministry.
“Terrorism will not pass! We will fight it resolutely,” said ministry spokeswoman Maria Zakharova.
“The memory of this outstanding Russian diplomat, a man who did so much to counter terrorism… will remain in our hearts forever,” she said.
US state department spokesman, John Kirby, said US officials were aware of reports about the attack on the ambassador.
“We condemn this act of violence, whatever its source,” he said. “Our thoughts and prayers are with him and his family.”
Video of the event shows Mr Karlov making a speech when gunshots ring out.
The camera pulls back to show a smartly dressed gunman, wearing a suit and tie, waving a pistol and shouting.
He can be heard yelling: “Don’t forget about Aleppo, don’t forget about Syria” and uses the Arabic phrase “Allahu Akbar” (God is great).