Congolese rebels say they are instituting a unilateral cease-fire around the eastern provincial capital of Goma to prevent panic as the army retreats and residents flee.

The rebels made the announcement Wednesday in a statement as gunfire crackled throughout the city, apparently from the retreating troops who residents said are out of control.

A U.N. spokesman welcomed the announcement but said it was not yet clear if the "simple declaration" was being followed by action.

Spokesman Madnodje Mounoubai confirmed that Goma was generally in a state of panic but confirmed the rebels were not in the city. He said peacekeepers were at the airport and at in other strategic points.

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Congolese soldiers in retreat from advancing rebels commandeered vehicles and fired wildly as they moved through the eastern provincial capital Goma on Wednesday and joined thousands of refugees struggling to stay ahead of the violence.

Gunfire crackled in the city, apparently from the retreating troops who residents said are out of control.

Refugees said the Tutsi rebels had already overrun Kibati, a village seven miles to the north that was housing thousands of people. They now are among the people streaming through the city.

Goma's governor Julien Mpaluku said panic was spreading. He said he could not confirm that the army had deserted Goma, but stressed that U.N. peacekeepers were still in charge and that rebels had not yet entered the city.

U.N. spokesman Madnodje Mounoubai confirmed the rebels were not in the city and said peacekeepers were at the airport and at in other strategic points.

Rebel leader Laurent Nkunda has threatened to take Goma despite calls from the U.N. Security Council for him to respect a cease-fire brokered by the U.N. in January.

The U.N. says its biggest peacekeeping mission — a 17,000-strong force — is now stretched to the limit with the upsurge of fighting and needs more troops quickly from wherever it can get them.

The Congolese army said troops from Rwanda had crossed the nearby border and attacked its soldiers earlier Wednesday, which raised tensions that could widen the conflict to include neighboring countries.

Rwanda's Tutsi-led government immediately denied its troops had attacked. But Congo turned to neighbor Angola for help "defending territorial integrity." One of the back-to-back wars that afflicted Congo from 1996 to 2002 embroiled eight African nations and became a rush at the country's vast mineral riches.

Angolan state radio indicated Congo was seeking primarily political and diplomatic support, but International Cooperation Minister Raymond Tshibanda asked the Angolan president Tuesday night for "a promise of engagement, help in saving lives, defending territorial integrity and establishing the state's authority throughout the country."

The U.S. State Department said Assistant Secretary of State for African Affairs Jendayi Frazer was heading to the Congolese capital Kinshasa and would arrive Thursday.

"There is a lot of violence," said department spokesman Sean McCormack. "This is of deep concern to us."

The deserting soldiers in retreat from advancing rebels entered the city along with fleeing refugees and grabbed private cars as well as taxis and motorbikes as they tried to leave the city by another route.

Residents who were reached by telephone said gunshots could be heard in several northern Goma neighborhoods. One said he had to run behind a wall to escape a barrage of gunfire and that the shooting was coming from Congolese army troops, out of control in retreat. People were holed up in the houses, fearing the army will loot, as it often does.

The residents spoke anonymously in fear of retaliation.

Nkunda says the Congolese government has not protected his minority Tutsi tribe from a Rwandan Hutu militia that escaped to Congo after helping carry out the 1994 Rwanda genocide in which half a million Tutsis were slaughtered.

The peacekeeping force's failure to halt the rebellion has enraged Congolese who attacked U.N. compounds in Goma with rocks this week. People regularly stone peacekeepers' vehicles.

U.N. Secretary-General Ban Ki-moon said Wednesday he was speaking to the presidents of Congo and Rwanda to resolve the crisis and that Europe and the United States plan to send diplomats to both countries to try to negotiate a peaceful solution. He spoke in Manila, the Philippines.

A bombardment outside Goma in the morning frightened tens of thousands of refugees and stirred dangerously growing anti-Tutsi sentiment in a region where decades of conflict with the majority Hutu reached a cataclysm in the 1994 genocide.

"It's the 'long noses' from Rwanda who are bombing us, the Rwanda Tutsi," refugee farmer Gaspar Sebigore shouted at a village overrun by people fleeing the fighting.

The tall, sharp-featured Tutsi used to be the aristocracy in the region and held sway over the Hutu, a generally shorter, stockier tribe with flat facial features.

In the days after the genocide, more than a million Hutus fled victorious Tutsi forces in Rwanda and came to Congo where they regrouped in a brutal militia that helps fuel the continuing conflict in eastern Congo.

Congo's army "wants to divert the international community's attention from the fact that they are collaborating with the masterminds of the Rwandan genocide, because the conflict in Congo revolves around those genocidal forces," Rwandan Maj. Jill Rutaremara told The Associated Press from Arusha, Tanzania, where he was attending a regional meeting on peace and security.

Nkunda's forces said Tuesday that the army had deserted numerous posts on the front line to be defended by Hutu militiamen, saying they had no choice but to fight this traditional enemy.