* Rebels say hold position outside city, fighting halted
* Spokesman says rebels do not plan to take Goma
* UN experts accuse Rwanda, Uganda of aiding M23 rebels
* Residents trying to leave city - Oxfam
Rebels in Congo, who U.N. experts say are backed by neighbouring Rwanda, reached the outskirts of the eastern city of Goma on Sunday after pushing back U.N. peacekeepers and government troops, but a spokesman said they did not plan to take the city.
In four days of battles, the rebels have advanced closer than at any time in their eight-month uprising to Goma, the provincial capital of North Kivu and home to the headquarters of the U.N. peacekeeping mission in eastern Democratic Republic of Congo.
Colonel Vianney Kazarama, spokesman for the M23 rebels, said fighters had advanced to within two kilometres of Goma. He said the rebels would hold their position around five km outside the city and that fighting had stopped for the day.
"We're not going to take the airport, we are responding to an attack by the army ... We're just doing this to break the capacity of the FARDC (Congolese army)," Kazarama told Reuters.
"The situation remains under control," he said later in a text message.
Earlier, Colonel Olivier Hamuli, a spokesman for the Congolese army, spoke to Reuters briefly by telephone before the line was cut. "There is combat about five km from the airport," he said.
U.N. peacekeeping spokesman Kieran Dwyer said from New York that "the rebels bypassed Kibati and are in the general area of Munigi, which is about seven km from Goma and close to the Goma airport."
"The United Nations peacekeeping mission, MONUSCO, engaged throughout the day supporting the FARDC to protect civilians and in self-defence, including carrying out sorties and firing from attack helicopter missions that have fired rockets and cannon rounds," Dwyer said in an email.
The United Nations has about 6,700 peacekeeping forces in North Kivu, with some 1,400 troops in Goma and the surrounding area. The force has a mandate to protect civilians.
"The situation in Goma is extremely tense," Dwyer said. "There is a real threat that the city could fall into the M23's hands and/or be seriously destabilized as a result of the fighting."
RWANDA, UGANDA DENY SUPPORTING M23
Goma, on the Rwandan border, is home to up to a million people, including hundreds of thousands displaced by conflict. M23 rebels have repeatedly said they do not intend to capture the city.
U.N. sanctions monitoring experts have accused Rwanda and Uganda of supporting the M23 rebels in eastern Congo. Last week the U.N. experts recommended that the Security Council sanction a number of Rwandan officials. Congo's government has also urged the council to sanction Rwandans accused of backing M23.
While Rwanda's army has repeatedly sent soldiers into Congo during nearly two decades of conflict in Africa's Great Lakes region, the Rwandan government has strongly denied supporting the M23 in the latest rebellion. Uganda has issued similar denials.
The U.N. peacekeeping chief Herve Ladsous told reporters on Saturday the M23 rebels have received sophisticated equipment, including night vision capacity and 120 mm mortars.
More than three-quarters of a million people have fled their homes since the latest fighting in eastern Congo erupted in April when a group of soldiers mutinied to form the M23 group.
The rebels accused Kinshasa of failing to respect a 2009 peace deal that ended a previous rebellion in North Kivu and integrated insurgents into the national army.
European Union foreign affairs chief Catherine Ashton called on the rebels to halt their offensive on Goma.
"We are particularly preoccupied by the fate of more than 70,000 internally displaced persons who have started leaving the camp of Kanyaruchinya, north of Goma," she said.
Tariq Riebl, humanitarian programme co-ordinator for Oxfam aid agency, said residents were trying to evacuate their families from Goma while trucks full of Congolese soldiers were seen leaving the city on Sunday.
"People are moving around the city. I do know a lot of people are sending their families out if they have the financial means to do that," Riebl said.
He said thousands of displaced people were also abandoning camps in the north of the city to avoid the advancing rebels.
"The question now is, what does this (fighting) mean? Are M23 going to take Goma, nobody knows," he said.
Thomas D'Aquin Muiti, president of a local non-governmental organisation in North Kivu province, said reassurances from the rebels that they would not enter the city were not to be trusted.
"I think everyone in the town is sceptical of M23 ... the town is emptying ... If the international community allows M23 to take Goma it'll be a humanitarian catastrophe" Muiti said.
More than 5 million people are estimated to have died from violence, hunger and disease in wars in Congo since 1998, which would make it the deadliest conflict since World War Two.