Rebels seized an east Congo army base and the headquarters of a refuge for some of the world's last mountain gorillas in heavy fighting Sunday that sent thousands of civilians fleeing, U.N. officials and rebels said.
An unknown number of soldiers, rebels and civilians were killed in the renewed fighting in North Kivu province, according to civilians.
Government troops raced down the road north from the provincial capital of Goma to reinforce a counterattack Sunday morning. One tank careened into a group of fleeing civilians and killed three teenage boys, civilians said.
Associated Press reporters who watched the fathers burying their sons in a cabbage patch outside Kibumba could hear bombing from army tanks about 12 miles from Rumangabo army camp, seized in the attack.
Sunday's attack marked the second time rebels have seized the base since Aug. 28, when rebel leader Gen. Laurent Nkunda went on the offensive after accusing government troops of violating a January cease-fire.
Congo's government said that two battalions of "foreign soldiers" helped Nkunda take Rumangabo on Sunday. It has said that Rwanda's Tutsi-dominated government sent hundreds of troops to fight alongside Nkunda in the first attack on the army base - allegations Rwanda denies and U.N. officials say appear unfounded.
But the rhetoric strengthens ethnic tensions amid fears Congo's conflict could again escalate beyond its borders. Back-to-back wars in Congo spilled into half a dozen neighboring countries and destroyed much of Congo itself by 2002.
Some 15,000 civilians escaped Sunday, the United Nations said, among more than 200,000 people who have fled their homes in two months and joining at least 1.2-million displaced in previous conflicts.
"There's heavy fighting. A lot of people have been killed - rebels, soldiers, civilians. We're lucky we got away," said Jean-Baptiste Bushu Mbusho, a builder who works for the Italian aid agency AVSI.
The U.N. force has failed to halt the fighting in the vast region of rural hills and forests, and both sides in the combat accuse the United Nations of siding with the other.
The United Nations deployed a rapid reaction force on Sunday and appealed to both sides to cease fire, at least to allow civilians to escape.
Park Director Emmanuel de Merode called the seizure of the headquarters "unprecedented, even in all the years of conflict in the region."
The park is home to 200 of the world's 700 remaining mountain gorillas, which are considered critically endangered. Ten mountain gorillas were killed last year, including two Silverbacks, causing an international outcry.