Khartoum - Peacekeepers said they saw Sudanese government aircraft bombing suspected rebel positions in the western Darfur region on Wednesday, days after negotiations between Khartoum and the insurgents resumed.

But Sudan's armed forces denied the reports, saying they had not carried out any out any operations around the town of Umm Baru, in North Darfur, the scene of recent clashes between the rebel Justice and Equality Movement and a group of former rebels backed by the government.

Members from the joint U.N./African Union UNAMID peacekeeping force said they heard five shell explosions in territory north of the town.

A UNAMID official, who asked not to be named, said it was thought the army was targeting JEM positions. No one was immediately available from JEM to comment.

Brigadier Uthman al-Agbash told Reuters no government bombing had taken place. "The Sudanese army did not have any military operations in this area" he said.

Aerial attacks are banned in Darfur by ceasefires and a U.N. Security Council resolution. Sudan's army has said it has used aerial attacks in the past.

JEM commanders said they defeated a force of fighters loyal to former rebel leader Minni Arcua Minnawi close to Umm Baru over the weekend. In 2006, Minnawi became the only Darfur rebel to sign a peace deal with the government and then became a presidential assistant.