A new attack by Ugandan rebels has left at least seven civilians dead in the restive east of the Democratic Republic of Congo, local officials say.

Amisi Kalonda, a top official in the regional hub of Beni confirmed on Sunday that the Allied Democratic Forces-National Army for the Liberation of Uganda (ADF-NALU) attacked an area near Mbau in the north of the troubled North Kivu Province.

The rebel group had killed some 20 people in North Kivu Province in a mid-April assault.

The rebels are accused of killing more than 400 people over the last 10 months.

More than 300 people were killed by ADF-NALU militants last year in and around Beni.

The ADF-NALU rebel group, which was founded in Uganda in 1995 and later moved to Congo, is believed to have roughly 400 members and has been accused of committing serious human rights violations, including recruiting child soldiers and rape.

ADF-NALU and dozens of other armed groups have been active in eastern Congo since the 1996-2003 Congo wars.

The Congolese army, joined by UN troops, is on the offensive against the rebel group which is blamed for more than two decades of violence that has forced hundreds of thousands of people to flee their homes.