When mostly Christian militias loyal to the ousted president launched an attack on the Central African Republic’s capital, Bangui, on the morning of Dec. 5, the Associated Press photographer Jerome Delay was in his hotel. Cut off from his driver because of the fighting, Mr. Delay walked and caught rides from pro-government forces instead.

Corpses were laid in front of Parliament, on the streets and inside a mosque where about 50 bodies of women and men were being prepared for burial. He found 200 more when he went to the morgue the next day.

“It was horrifying. I’m an old hand in a way, and so as terrible as it sounds, I’m used to the smell of death,” said Mr. Delay, who is 53. “But that was unbearable. Absolutely unbearable.”

And all too familiar.

He has been based in South Africa for the last eight years, covering, among other things, Mali and the conflict in Congo, where he witnessed atrocities on an almost-unimaginable scale. Years before, he said in a phone interview from Bangui on Sunday, he was haunted by the screams of wounded, hospitalized babies during the siege of Sarajevo in the early 1990s.

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A few hours after photographing inside the mosque, he found out that Nelson Mandela had died. His first thought was, “I am at the wrong place at the wrong time — how am I going to get out of here?”

He wanted to record the events surrounding Mr. Mandela’s death because “he represented the best of humanity,” and Mr. Delay was to be a key player in The Associated Press’s coverage. He called his boss in London, and they began to make plans to get Mr. Delay safely out of the Central African Republic and to South Africa.

But in the morning Mr. Delay saw things differently. He still wanted to be one of the hundreds of photographers covering the historic moment of Mr. Mandela’s funeral. But as one of a handful of international photographers working in Bangui, he felt a responsibility to stay put.

Mr. Delay remembered how international photojournalists converged on South Africa in 1994 to “cover the elections and no one saw Rwanda coming.”

“We are on the brink of a humanitarian catastrophe of enormous proportions,” Mr. Delay said. “I really think my responsibility is to be here and to try even harder to put this place and these people on the map, one picture at a time.”

The Central African Republic is one of the poorest countries in the world, with a population of 4.6 million people, about 10 percent of whom have been driven from their homes. The latest of many coups, last March, involved a coalition of mostly Muslim rebel groups, called Seleka, led by Michel Djotodia. After their victory, human rights violations followed from all sides of the conflict.

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Mostly Christian groups have battled the Seleka forces, and there has been an escalating cycle of revenge killings along religious lines from both sides. France has committed 1,600 troops to try to prevent further atrocities in this mostly Christian country, but it has had difficulty containing the violence.

Despite that, Mr. Delay has spent the last two weeks filing dramatic images that have made clear the atrocities happening in the Central African Republic. They have appeared on front pages of newspapers and websites across the world and on television, bringing attention to the conflict.

On Sunday, Mr. Delay had what he said had been “a very quiet day.” He photographed mobs stabbing and beating people and African Union forces shooting back at the crowds.

He then went to photograph the anti-Balaka mostly Christian militia in the woods outside of Bangui, where he found very young soldiers wearing charms around their necks to make them invincible and bearing makeshift guns, bows and arrows, sticks and machetes. Later in town, he photographed the remnants of the deposed president’s army.

“These are things I haven’t seen in years,” he said. “That’s a power that we have. And I think we need to be engaged, responsible journalists. And I get the feeling that it’s working.”

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