Kinshasa - Diplomats have expressed serious concern over recent fighting in the east of the Democratic Republic of Congo and called on warring forces to respect a January ceasefire.

Rebels aligned with rogue general Laurent Nkunda and government soldiers have been involved in firefights in the eastern North Kivu province.

The United Nations' peacekeeping mission in the DR Congo (MONUC) has also fired warning shots at troops from Nkunda's Congres National pour la Defense du Peuple (CNDP) to prevent them from from capturing new territory.

Thousands have fled the fighting into neighbouring Uganda.

The January peace accords were designed to end sporadic clashes that occurred in 2007, four years after the war in the sprawling DR Congo officially ended, but the recent violence has led to concern that a fresh conflict could break out.

"The International Facilitation calls on all signatories to scrupulously respect the provisions of the Actes d'engagement, in particular the immediate cessation of hostilities," a group of diplomats representing the African Union, European Union and UN, said in a statement.

"The International Facilitation condemns all cease-fire violations and demands that the CNDP immediately ceases its military activities in areas recently occupied," the statement continued.

However, the diplomats exempted troop movements aimed against the Hutu Forces Democratiques pour la Liberation du Rwanda (FDLR), a group implicated in the 1994 massacre in neighbouring Rwanda.

The DR Congo's army (FARDC) and UN peacekeepers are supposed to be launching operations against the FDLR, but independent watchdog Global Witness said Wednesday that Congolese soldiers were collaborating with the FDL in order to profit from gold and tin mining.

Over 5 million people are estimated to have died as a result of the long conflict in the resource-rich Central African nation.

The conflict is often referred to as the African World War due tothe large number of different armed forces involved. (dpa)