Ankara, Turkey (CNN) The Associated Press photographer who captured images of Russian ambassador Andrey Karlov's assassination at an art exhibition in Ankara has recalled the terrifying moment the gunman opened fire.

"I heard shots, very loud -- bam bam bam," Burhan Ozbilici told CNN.

"The people standing in front they disappeared. They threw them(selves) on the floor. They were trying to hide, to take shelter. I was shocked ... afraid ... not panicked."

A man identified as Mevlut Mert Altintas stands over Andrei Karlov, the Russian Ambassador to Turkey, after shooting him at a photo gallery in Ankara, Turkey on December 19, 2016.

Ozbilici hadn't planned to attend the new photo exhibition in the Turkish capital but made a snap decision to stop in on his way home from the office. With Russia-Turkey relations appearing to thaw in recent weeks, the AP photographer thought some images of Karlov speaking at the gallery might be useful in the near future.

"He was very soft, calm, a very natural man. Not a diplomat we usually see."

'I have a responsibility to record the event'

But in the blink of an eye, the tranquil scene in the gallery was shattered. Gunshots rang out and people scattered as a blind panic hung in the air.

Ozbilici scrambled to the back of the showroom, finding partial refuge behind a wall. He watched as the gunman walked around the ambassador's body, describing him as agitated as he ripped several of the photographs on display off of the wall.

People react after Russian Ambassador to Turkey, Andrei Karlov, was shot at a photo gallery in Ankara, Turkey, on December 19, 2016.

"In difficult situations, I'm calm. I have a responsibility to record the event," he told CNN. "The ambassador was lying on the ground -- not moving. And the (shooter) was making (a) politically-motivated speech.

He added: "Some people were screaming, crying, so i could not hear well."

"I was, of course, fearful and knew of the danger if the gunman turned toward me," he wrote earlier on APNews.com . "But I advanced a little and photographed the man as he hectored his desperate, captive audience."

Karlov lies on the ground as a man with a pistol -- later identified as police officer Mevlut Mert Altintas -- gestures at the scene on December 19.

"This is what I was thinking: 'I'm here. Even if I get hit and injured, or killed, I'm a journalist. I have to do my work. I could run away without making any photos ... But I wouldn't have a proper answer if people later ask me: 'Why didn't you take pictures?'"

He added: "I even thought about friends and colleagues who have died while taking photographs in conflict zones over the years."

All the while, Ozbilici continued working, documenting the political assassination from a perspective that would lead news outlets across the globe within hours.

The gunman gestures shortly after Karlov was shot on December 19, 2016.

"As my mind raced, I saw that the man was agitated -- and yet, he was, strangely, in control of himself. He shouted at everyone to stand back. Security guards ordered us to vacate the hall and we left."

Ozbilici told CNN it wasn't until later when he began editing his photos that he truly comprehended the premeditation behind the shooter's calculated attack.

"When I got back to edit my photos, I saw (in) my two very first photos (that) the gunman was standing behind ambassador ... like he was part of embassy staff or somebody from the art gallery -- very calm.

"I felt very bad to see an innocent man lying on the ground... lifeless."

Karlov moments before he was gunned down while speaking at a new photo exhibition in Ankara, Turkey. The gunman is seen at rear on the left.

Hailed as a 'hero'

Within minutes of their release, Ozbilici's photographs spread like wildfire through social networks.

Photographers and journalists the world over praised his composure in the face of terror.

What bravery AP's @BurhanOzbilici showed to capture those photos. Wire staff very often unsung and very often the heroes of this trade. pic.twitter.com/JYpXbrxIUm — Barry Malone (@malonebarry) December 19, 2016

"What bravery AP's @BurhanOzbilici showed to capture those photos. Wire staff very often unsung and very often the heroes of this trade," wrote Barry Malone , online editor at Al Jazeera English.

Before I die, may I know one-hundredth of @BurhanOzbilici's courage. https://t.co/khFayfxtK1 — Bronwen Dickey (@BronwenDickey) December 19, 2016

Journalist Bronwen Dickey wrote on Twitter : "Before I die, may I know one-hundreth of @BurhanOzbilici's courage."

Awed by the courage of the photographer who captured this terrifying shot https://t.co/7ux2Z5rU8c (Credit: Burhan Ozbilici/AP) pic.twitter.com/1vS475mtJQ — Hiroko Tabuchi (@HirokoTabuchi) December 19, 2016