At least eight people have died in fighting between rival factions of M23, the most powerful rebel group in the Democratic Republic of Congo.
The fighting late Sunday in the eastern city of Rutshuru, a rebel stronghold, appeared to reveal tension within the rebel group, which is holding peace talks with the DRC government in Uganda.
Sources say the clash involved fighters loyal to General Sultani Makenga, the military chief of M23, and supporters of another M23 leader.
The clashes came a day after regional leaders from 11 African countries signed a peace deal aimed at ending decades of conflict in mineral-rich eastern Congo.
Among other things, the deal calls for countries in the region to not interfere in each other's affairs. A U.N. panel of experts accused Rwanda and Uganda of helping M23, an accusation both countries have denied.
The DRC has endured armed conflicts for more than two decades, especially in the mineral-rich areas in the east of the country.
More violence erupted last April, and M23 rebels captured several cities in November, demanding the government fully implement a 2009 peace deal designed to integrate rebels into the Congolese army.
Leaders of Africa's Great Lakes region will meet again in Kampala on March 15 to continue discussions with M23 rebels.
Some information for this report was provided by AFP and Reuters.