By Yves Boussen and Hez Holland
GOMA, Congo, Oct 29 (Reuters) - Congolese rebels declared a ceasefire on Wednesday after a four-day push to the gates of Goma that threatened to drag Congo back to all-out war, but heavy gunfire resumed near the eastern city after dark.
The Tutsi rebel offensive in North Kivu province has threatened to overwhelm the world's biggest peacekeeping force, with 17,000 U.N. troops based mainly in eastern Congo where fighting has flared sporadically since a 1998-2003 war.
U.N. Secretary-General Ban Ki-moon said the rebels' four-day offensive was "creating a humanitarian crisis of catastrophic dimensions and threatens dire consequences on a regional scale".
The National Congress for the Defence of the People (CNDP) rebel group declared a ceasefire, but a Reuters reporter heard gunshots in Goma after dark and artillery fire a few km (miles) away near the Rwandan border. Goma residents reported looting.
"We are in effective control of Goma and we want the U.N. forces, MONUC, to secure Goma city and restore peace with the help of the national police force of DR Congo," rebel leader General Laurent Nkunda told Reuters after the ceasefire.
Earlier, thousands of civilians and hundreds of Congolese government soldiers poured into Goma from the north, where the army has clashed with Nkunda's forces.
Many residents left town carrying belongings on their heads.
Some 45,000 civilians fled to Goma from two camps at Kibati 10 km (6 miles) to the north on Wednesday after heavy fighting between the army and CNDP forces, refugee agency UNHCR said.
The U.N. force, MONUC, has backed Congolese troops against the rebels but the head of the U.N. force said it was "stretched to the limit". A request to the U.N. Security Council for reinforcements has not yet been met.
France, the current holder of the European Union presidency, said it was discussing sending an EU force of a few hundred men to Congo but that several countries opposed the idea.
"We have discussed a group that is called the tactical group. This tactical group is a military guard which on a rotating basis can offer between 400 and 1,500 men whom we could deploy in the name of Europe within eight to 10 days," French Foreign Minister Bernard Kouchner told reporters in Paris.
A Western diplomat said the toughest opposition to the plan came from Germany. The CNDP ceasefire was a result of direct talks between Nkunda and MONUC head Alan Doss, and of Rwanda encouraging Nkunda not to invade Goma, the diplomat said.
PANIC IN BORDER CITY
Congolese army troops abandoned the town of Rutshuru, 70 km (45 miles) to the north of Goma, to a rebel advance, although MONUC troops said they retained their positions in the town.
The advance on Goma, a major crossing point and tin trading centre on the Rwandan border, sparked panic and accusations that the U.N. force was not doing enough to fight off the rebels.
Civilians attacked a convoy evacuating U.N. civilian staff from the mission's headquarters near Goma airport to a compound on the shore of Lake Kivu on Wednesday.
"It was pretty horrible ... angry youths threw large stones. Windscreens and windows were broken, but I don't think anyone was hurt," said a U.N. staff member in the convoy.
Neighbouring Rwanda, whose 1994 genocide is intricately tied up with years of ethnic bloodshed in eastern Congo, accused Congolese forces of shooting across the border, while the Congolese army said it had been attacked from Rwandan soil.
"We have no evidence that Rwanda is fighting directly in the conflict in east Congo. We do believe that Rwandan territory is being used to support the CNDP," U.S. Assistant Secretary of State for African Affairs Jendayi Frazer told journalists.
The CNDP accuses Congo's army of collaborating with the Democratic Forces for the Liberation of Rwanda (FDLR), which includes Hutu militiamen and former Rwandan soldiers who took part in Rwanda's 1994 genocide of Tutsis and moderate Hutus.
"A big concern is how Rwanda will act at this stage. If they feel threatened or there are acts against the Tutsis, I think this would be a red line for Kigali," a diplomat in Congo said.
A Congolese government minister met Angolan President Jose Eduardo dos Santos in Luanda on Tuesday to ask for help solving the conflict, state-owned Jornal de Angola said on Wednesday.
Angola, left with one of Africa's biggest armies after a 27-year civil war, backed Kinshasa in Congo's 1998-2002 war.
Around 250,000 civilians have fled their homes in North Kivu since a January peace deal collapsed in August. Nearly 850,000 had been displaced in the previous two years, the United Nations says. Congo's 1998-2003 war and the resulting humanitarian crisis have killed an estimated 5.4 million people.