National park rangers here are battling to save a 2-month-old gorilla found clinging to its dead mother, who was shot dead through the back of the head.
"She's more or less OK. It is certainly a worrying situation, but not hopeless," Paulin Ngobobo, senior warden in eastern Congo's Virunga National Park, said from the city of Goma, where he is looking after the female infant.
He said the young mountain gorilla, born on April 15 and named Ndakasi by conservationists, had accepted baby formula from a feeding bottle. Mountain gorillas usually suckle for up to three years in the wild.
Only 700 mountain gorillas survive in the wild, more than half of them in Virunga.
At least two have been killed and eaten already this year by rebels living off the land as militia fighting drags on despite the official end of Congo's five-year war in 2003, in which violence, hunger and disease killed around 4 million people.
It was unclear who had killed the adult female or why. She had been killed "execution-style" in the back of the head and left at the scene rather than taken away to be eaten, said Emmanuel de Merode of conservation group Wildlife Direct.
"It looks like she was lured with bananas because we found bananas at the site," de Merode said from Goma.
"She was shot at very close range ... a second gorilla was probably shot because there was a trail of blood nearby and three gunshots were heard. The other was probably wounded and got away," he said.
"There are militia groups there. This particular incident was in the Mikeno sector, which is on the border of Rwanda. There was a lot of fighting in that area in January and those problems have not entirely been solved," he said.
Last month Mai Mai rebels attacked patrol posts in Virunga park, killing one wildlife officer and critically injuring three others, and threatened to slaughter gorillas if park rangers retaliated, Wildlife Direct said at the time.
More than 150 rangers have been killed in the last decade while protecting Congo's parks from poachers, rebel groups, illegal miners and land invasions, working through the war without pay, Wildlife Direct said.