Two factions of the Congolese rebel group M23 have been fighting each other in the east of the Democratic Republic of Congo.
Hundreds of fighters from one group are now on the run, after the split resulted in battles between the two in February.
The split came as peace talks in neighbouring Uganda were concluding, and those who fled DR Congo are now in Rwanda.
The renewed fighting caused civilians to flee the fighting, too.
"We fight them and during the fight they lost. They were totally defeated. They had to leave the ground, the land, the area of M23, and now they are out, they are running away," said Rene Abandi, the head of M23's dialogue delegation in Uganda.
The breakaway faction was led by General Bosco Ntganda, who is wanted by the International Criminal Court on war crimes charges.
Some of his men have surrendered to UN peacekeepers, while others have fled into neighbouring Rwanda. DR Congo says that Ntganda is in Rwanda, too.
The fighters include M23's ex-political leader Jean-Marie Runiga, whose faction has been fighting rivals loyal to the rebel group's military chief, Sultani Makenga, since March 9.
A Rwandan military spokesman said the army was "handling (the refugees) under the international law, we disarmed them upon arrival and separated the fighters from civilians."
Peace talks in Kampala, the Ugandan capital, are expected to resume within a week.