The photographer who captured dramatic images of the moment Russian ambassador Andrey Karlov was assassinated in Turkey, has described the shooter as "agitated".

Burhan Ozbilici was simply on his way home from the offices of Associated Press when he decided to drop by the "From Kaliningrad to Kamchatka, from the eyes of travellers" photo exhibition – an event aimed at inspiring shared understanding between Russia and Turkey.

Ozbilici said Andrey Karlov spoke "lovingly about his homeland" before a security guard later identified as Mert Altıntaş shot him repeatedly.

"The event was routine enough," Ozbilici said, in a piece for AP. "[It was] the opening of an exhibit of photographs of Russia – so when a man on stage pulled out a gun I was stunned and thought it was a theatrical flourish.

"It was anything but. Moments later the Russian ambassador was sprawled on the floor and the attacker was waving his gun at the rest of us, shouting slogans.

"He shot the ambassador at least once more at close range and smashed some of the framed photos on the wall. In all there were at least eight shots.

"Guests ran for cover, hiding behind columns and under tables. I composed myself enough to shoot pictures."

It would transpire that Altıntaş shouted religious slogans and, "Don't forget Aleppo. Don't forget Syria!" after he shot the 62-year-old ambassador.

Ozbilici described the shock and panic that followed the shooting.

"Suddenly, gunshots rang out in quick succession, followed by panicked audience members running for cover," Ozbilici said. "The ambassador's body lay on the blood-splattered ground.

"It took me a few seconds to realise what had happened: A man had died in front of me; a life had disappeared before my eyes.

"I was shocked and sad but I started to take photographs, sheltering behind a wall.

"The gunman was agitated. He circled the body, smashing some of the photos hanging on the wall. He shouted at everyone to stand back and pointed his gun at us. Security guards ordered us to vacate the hall and we left.

"Ambulances and armoured vehicles soon arrived and the police operation was launched.

"When I returned to the office to edit my photos, I was shocked to see that the gunman was actually standing behind the ambassador as he spoke."

Andrey Karlov Mevlut Mert Altintas ambassador
The gunman has been identified as 22-year-old riot police officer, Mevlut Mert Altintas Hasim Kilic/Hurriyet