Qatar strongly condemned and denounced the assassination of Russian Ambassador to Turkey Andrey Karlov.

In a statement, Qatar’s Foreign Ministry said the incident was a criminal act that contradicted all divine religions, human values and diplomatic norms.

The 62-year-old administrator was shot in the back while giving a speech at an art gallery in the Turkish capital of Ankara.

Security sources said the gunman, who shouted ‘Don't forget Aleppo’, was an off-duty police officer.

The Russian foreign ministry confirmed the death and it marks one of the most serious spillovers of the Syria conflict. It could have wide resonance throughout the region.

Russia is a close ally of Syrian President Bashar Al Assad and its air strikes were instrumental in helping Syrian forces end rebel resistance in the northern city of Aleppo. Turkey president Tayyip Erdogan, on the other hand, has been a vociferous opponent of Assad.

“We regard this as a terrorist act,” said Russian Foreign Ministry spokeswoman Maria Zakharova. “Terrorism will not win and we’ll fight against it decisively,” she said.

The attacker was smartly dressed in black suit and tie, and standing behind the ambassador as he made his speech at an exhibition, a person at the scene said.

“He took out his gun and shot the ambassador from behind. We saw him lying on the floor and then we ran out,’ said the witness.

Two security sources identified the gunman as an off-duty police officer who worked in the Turkish capital. Security officers responding to the attack killed the assailant.

It was not immediately clear who was behind the attack or whether the gunman acted in isolation.