By Chrispin Mvano
GOMA, Democratic Republic of Congo (Reuters) - Two days of clashes between Congo's army and rebel fighters near the eastern city of Goma have killed at least 19 people, threatening an uneasy six-month peace just days before a scheduled visit by U.N. Secretary-General Ban Ki-moon.
Government forces and the M23 insurgents began exchanging heavy weapons fire for a second day early on Tuesday, with explosions still being heard late into the afternoon.
A Reuters witness saw rebel fighters blocking the road heading north away from the city, as civilians streamed out of combat zones clutching their belongings and driving their livestock in front of them.
"The M23 tried to overrun our positions and we're in the process of pushing them back," army spokesman Colonel Olivier Hamuli told Reuters. "We're very confident (of defending Goma)".
Government spokesman Lambert Mende said 15 rebels and four government soldiers had been killed in Monday's clashes north of Goma, the biggest city in the east of Democratic Republic of Congo.
Details of casualties from Tuesday's fighting were not immediately available, but both military and rebel sources said the shelling had caused further deaths.
The fighting was the first since November, when M23 troops routed Democratic Republic of Congo's army - the FARDC - and briefly seized Goma, despite the presence of thousands of U.N. peacekeepers.
M23 spokesman Amani Kabasha denied starting the clashes, saying the rebels had come under heavy army shelling for a second day and the group's military commander, Sultani Makenga, had given the order to respond.
"It seems the government wants to fight," he said. "There is no political will for bringing peace through a negotiated settlement".
During its year-long insurgency, the M23 has repeatedly used alleged army aggression as a pretext to launch offensives, but has been weakened in recent months by infighting and defections. The Congolese army is also struggling to reorganize after its humiliating defeat in Goma last year.
U.N. experts accused Rwanda of sending troops and weapons across the border to support the M23 last year. Rwanda denies the accusation.
Peace talks between the M23 and the Congolese government in Kampala, the capital of neighboring Uganda, have stalled.
M23 is mainly made up of the members of a previous Tutsi-dominated rebel group which integrated into the ranks of the army following a 2009 peace deal.
But they deserted en masse last year and have stepped up training in their strongholds in preparation for the deployment of a U.N. Intervention Brigade with a mandate to neutralize armed groups across the region.
The U.N. brigade will count some 3,000 troops from South Africa, Tanzania and Malawi operating alongside the existing 17,000 strong peacekeeping mission.
Ban is due to arrive in Goma this week with the president of the World Bank as part of a high-profile visit to push for an end to nearly two decades of violence in the mineral-rich region which has left millions dead.
On a stopover in Mozambique on Tuesday, Ban described the situation in eastern Congo as "very dangerous" and said he hoped to deploy the Intervention Brigade "as soon as possible".
He said he had already appointed a force commander but gave no more details on the deployment timing.
(Additional reporting by Jonny Hogg in Kinshasa and Marina Lopes in Maputo; Editing by Jon Hemming)