Thousands of Congolese villagers fled to Uganda Thursday night as fighting broke out, the BBC reported.
The fighting started Thursday night in the North Kivu province and was reported to be continuing Friday.
A military spokesman said about 100 defected soldiers have turned themselves in and surrendered their weapons. About 900 soldiers remain at large.
Last week, the army gave soldiers who defected last month five days to surrender. The defected soldiers are loyal to Bosco Ntaganda, also known as the "Terminator," who is wanted by the International Criminal Court for alleged war crimes.
The ICC has accused Ntaganda of recruiting child soldiers for the rebel group the National Congress for the Defense of the People.