A government offensive against a rebel group in central Darfur has intensified in the past few days, a United Nations official said Friday. Samuel Hendricks, a United Nations humanitarian official, said the fighting in a stronghold of the Sudan Liberation Army in Jebel Marra had escalated, with confirmed reports of aerial bombardments in Deribat and two other surrounding areas. The Sudan Liberation Army has rejected the truce signed by the government and another rebel group on Tuesday in Qatar.