The impoverished central African country has been wracked by conflict near its eastern border, with many of the militias having evolved from the two Congo wars (1996-1997 and 1998-2003).

"The DRC armed forces launched large-scale operations overnight Wednesday to eradicate all domestic and foreign armed groups that plague the east of the country and destabilise the Great Lakes region," General Richard Kasonga, spokesman of the Congolese army, told AFP.

"The operation was launched from Nyaleke (Beni region), where artillery shelled rebel positions," he said. "Ground troops have been engaged since this morning."

The Beni region, in the North Kivu province which borders Uganda and Rwanda, has been particularly affected by militia violence.

An Islamist-rooted Ugandan armed group, the Allied Democratic Forces (ADF), has targeted Beni, killing hundreds of civilians over the last five years. The Democratic Forces for the Liberation of Rwanda (FDLR) are also active in the region.

The Congolese army shared a video with the media showing tanks firing shells and soldiers taking positions on a dirt road in a mostly deserted village. Scattered gunfire could be heard in the background.

Five Great Lakes countries -- the Democratic Republic of Congo, Burundi, Rwanda, Tanzania, Uganda -- decided last week to combine their military operations in the region.

The UN's peacekeeping mission in DR Congo has supported DRC troops in the region, but has ruled out backing any foreign intervention.