M23 group denies allegation of killing 50 civilians in eastern Kishishe village but confirms fresh fighting with DRC's military in North Kivu province that borders Uganda and Rwanda.
The Democratic Republic of Congo's (DRC) military has accused M23 rebels of killing 50 civilians and breaching a five-day-old truce in the country's restive east.
General Sylvain Ekenge said on Thursday the M23 group was "carrying out massacres... the most recent of which is that of 50 Congolese civilians, heinously murdered on Tuesday in Kishishe," a village some 70 kilometres north of the eastern city of Goma.
Ekenge claimed that while DRC forces had "scrupulously observed the truce", the M23 had attacked government positions.
The rebel group issued a statement denying the alleged massacre of civilians.
"The M23 Movement rejects the baseless allegations made against it in Kishishe," said the group's political spokesperson, Lawrence Kanyuka.
"The M23 reminds the international and national community that it has never targeted civilian populations," he said.
Sources said earlier that fighting had resumed on Thursday in Kirima in the same region, about 10 kilometres from the town of Kibirizi.
Paul Lutibahwa, head of civil society groups for the Bambo region, said: "The rebels have crossed the bridge, heading for Kibirizi... there's panic".
A security official, speaking on condition of anonymity, accused the M23 of having breached the ceasefire and "carrying on looting and fighting".
The M23's military spokesperson, Willy Ngoma, contacted by the AFP news agency, confirmed that there was fighting with the army.
Until Thursday's violence, there had been no fighting between government forces and the M23, although the rebels had clashed with local militia, especially in the Bambo area, where civilian casualties were reported.
The Vatican, meanwhile, announced that Pope Francis would visit the DRC and South Sudan from January 31 to February 5.
His trip to the two violence-plagued countries had been planned for July this year but was postponed because of treatment for knee pain.
His stay in the DRC from January 31 to February 3 will take place in Kinshasa and no longer include Goma.
The site that had been chosen for a papal mass, located 15 kilometres north of Goma, is currently occupied by a forward position of the armed forces.
Some 120 armed groups menace eastern DRC, making it one of Africa's most violent regions.
The March 23 movement, or M23, is a predominantly Congolese Tutsi rebel group that was dormant for years.
Kinshasa accuses its smaller neighbour Rwanda of supporting M23, something that UN experts and US officials have also pointed to in recent months.
Kigali disputes the charge, and in turn accuses Kinshasa of collusion with the FDLR — a former Rwandan Hutu rebel group established in the DRC after the genocide of the Tutsi community in 1994 in Rwanda.
Talks between the two countries in the Angolan capital of Luanda unlocked a truce agreement on November 23.
The ceasefire was scheduled to take effect on Friday, November 25 and be followed by a pull-out by the M23 two days later.