Ten civilians were killed when government forces fired on the rebel base in Kitagoma, in eastern Congo, near the border with Uganda, said M23 political branch spokesman Bertrand Bisimwa Saturday. He said the attack was on Friday.
"Our forces did not fight back and only protected themselves," said Bisimwa. "The M23 considers this provocation as a violation of the ongoing ceasefire and grants itself the right to respond and push back the threat as far as possible to protect the civilian population."
The Congolese army denied the attack.
"Kitagoma is under M23 control and far into their territory, it is impossible for us to go there. It is the M23 that has massacred civilians and is blaming us for it," said Col. Olivier Hamuli, spokesman for the Congolese army in North Kivu province.
The M23 is a rebel group made of former Congolese army officers who defected in April. They say they rebelled because the government failed to comply with a peace agreement signed in March 2009. The M23 controls a small part of North Kivu province, 30 kilometers (18 miles) north of Goma, the provincial capital.
Rwanda and Uganda have been accused by United Nations experts of supporting the rebels. A ceasefire was observed by the Congolese army and the M23 for two months as talks were held in Kampala between neighboring countries to try to find a diplomatic solution.
The M23 have been calling for direct negotiations with the Congolese government but President Joseph Kabila's government has so far refused to meet with the rebels.
"This is not a new situation for us, the government's will to start the war again has been visible since the day it refused to dialogue in Kampala. We spent 103 days in Kampala waiting for a direct dialogue with the Kinshasa government," said rebel spokesman Bisimwa.
Tension has been mounting in the past weeks as troops on both sides have sparked skirmishes along the edges of the rebel territory.
Troop movements have been visible on the road between Goma and Rutshuru, the rebel heaquarters, but both sides deny wanting to resume fighting.
"If the government wants to resume the war, we will fight back," said Col. Vianney Kazarama, of the M23 military branch, echoing the words of his Congolese army counterpart.
(Copyright 2012 by The Associated Press. All Rights Reserved.)