Government troops and unidentified rebel forces clashed in eastern Democratic Republic of Congo Sunday, military officials said.

Heavy weapons fire could be heard after 9:00 pm (1900 GMT) at Sake in North Kivu region, about 30 kilometres (20 miles) west of the city of Goma, officials and residents said.

A regional military official confirmed the fighting to AFP but could not identify the rebels.

There were no immediate reports of casualties.

The M23 rebel group controls part of the Democratic Republic of Congo's restive east.

Army tanks left Goma for Sake late in the evening.

The M23 was formed in May by former fighters in an ethnic Tutsi rebel group that was integrated into the military under a 2009 peace deal whose terms the mutineers claim were never fully implemented.

It controls a part of North Kivu's Rutshuru territory, and has been accused of human rights violations by the United Nations and activists.

The group denies those accusations.