A local journalist, Alain Mirova, has told the BBC that “many people are fleeing” hostilities, after weeks of calm in the area.

A local civil society group is cited by the media as saying that the rebels first attacked the army's positions before the fighting escalated.

The M23 has been in control of the border town of Bunagana and areas around it since June.

In a statement the rebels said the army launched attacks on their position on Thursday afternoon.

This comes weeks after a Kenyan army contingent was deployed in the area following a decision by neighbouring heads of states to send a regional force to fight rebels in eastern DR Congo.

It is not yet clear if the Kenyan force will be engaged in the new fighting.

DR Congo accuses Rwanda of supporting the M23 rebels, allegations that Rwanda has continuously denied.