Villages in the mountains of eastern Congo that once housed tens of thousands of people were nearly deserted Monday after Congo's army clashed with rebels in some of the worst fighting in a week.

The battles north of the eastern provincial capital of Goma came even as rebel leader Laurent Nkunda promised a U.N. envoy he would support a cease-fire as well as U.N. efforts to end the fighting that has displaced 250,000 people since August.

The few people remaining in Kanyabayonga were preparing to leave Monday, packing yellow jerry cans and bedrolls before setting off on foot. Congolese army soldiers also were seen fleeing the rebel advance.

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The two sides battled Sunday night about 10 miles from here in Rwindi. About 150 people took refuge outside a U.N. peacekeeping base, huddling beside a shipping container as mortar shells and artillery fire rained down.

"These blue helmets would not let us inside, but it's better than nothing," said Clement Elias, 20, referring to the U.N. peacekeepers. He said he heard 100 explosions Sunday night.

There was no immediate word on casualties, according to U.N. peacekeeping spokesman Col. Jean-Paul Dietrich.

"Everybody is trying to push the other side back," Dietrich said. "It's very regrettable that they could not respect the cease-fire."

On Monday, Rwindi was quiet but rebels were seen walking freely, carrying generators and boxes of ammunition. The town is tiny, housing little else but a headquarters for Virunga National Park and a peacekeeping base, which is surrounded by barbed wire and sandbags.

Dozens of civilians were sitting under trees Monday, listening to the radio for news. Rwindi is about 75 miles north of Goma.

The Central African nation has the world's largest U.N. peacekeeping mission, with some 17,000 troops, but the peacekeepers have been unable to either stop the fighting or protect civilians caught in the way.

On Sunday, the U.N. envoy, former Nigerian President Olusegun Obasanjo, met with Nkunda for the first time, after speaking with President Joseph Kabila.

Nkunda launched a rebellion in 2004, claiming to protect ethnic Tutsis from Hutu militias who fled to Congo after Rwanda's 1994 genocide left more than 500,000 Tutsis and others slaughtered. But critics say Nkunda is more interested in power and Congo's mineral wealth.

Fighting among armed groups has ground on for years in eastern Congo's lawless North Kivu province, but the violence sharply escalated in August.

Congo's government says it is willing to meet Nkunda, but only with the many other militias in the region. Nkunda has criticized the government for signing deals with Chinese companies to exploit Congo's cobalt and copper.

Some fear Congo's current crisis could once again draw in neighboring countries. Congo's devastating 1998-2002 war split the vast nation into rival fiefdoms and involved half a dozen African armies.