They said there was fighting on at least two fronts.

The M23 said it was committed to a peaceful solution but would continue to defend itself if attacked by the Congolese military or its allies.

The M23 and the army have accused each other of launching attacks on Monday, which led to significant civilian displacement.

Rwanda denies backing the M23 which has captured large swathes of territory over the past year and is threatening the regional capital, Goma.