The fighting in the Masisi region of North Kivu began late on Sunday and forced thousands of residents to flee their homes, some of them into neighbouring Rwanda, said aid groups.
General Bosco Ntaganda fought the government as a rebel before he was integrated into the army alongside other insurgents as part of a 2009 peace deal.
But clashes erupted again after President Joseph Kabila announced in mid April that he would try to arrest Ntaganda, a divise figure who has been at the heart of the region’s instability, “because the whole country wants peace”.
“We’re in control of the situation, we’re managing everything,” a senior military source told Reuters, asking not to be named. “The population should flee so they don’t get caught in the crossfire,”
He said at least five soldiers loyal to Ntaganda were killed on Sunday in Congo’s east – an area that remains haunted by myriad rebel groups left over from a devastating 1998-2003 war.
The source said Ntaganda’s forces had seized some territory from the government during the clashes.
Thousands of civilians in the region were fleeing toward the town of Goma, said Alexandre Essome, a spokesman for the U.N. peacekeeping mission in Congo known as MONUSCO.
“There’s still fighting ongoing. MONUSCO are deployed in all the villages around Masisi to ensure the protection of the population,” Essome said by telephone from Goma.
By early Monday evening more than 1,500 refugees had crossed into Rwanda, according to the United Nations, and more were waiting at the border according to Jean Claude Rwahama, the Rwandan director of refugee affairs.
The ICC has been seeking Ntaganda’s arrest for six years on charges he recruited children to fight in a bloody ethnic conflict in northeastern Congo that grew out of the broader civil war. Ntaganda denies involvement in war crimes.
Kabila had previously resisted international calls for his arrest, saying Ntaganda was a lynchpin in the fragile peace deal that integrated his fighters.
In recent weeks hundreds of soldiers loyal to Ntaganda have defected from the armed forces.
“He’s flexing his muscles. If other (soldiers) decide to join him, then yes, this could spread,” said a western observer, who asked not to be named.
Analysts and rights groups have accused Ntaganda of operating criminal networks in eastern Congo responsible for much of the instability that has troubled the region in recent years.