Darfur rebels accused Sudan government forces today of bombing their territory, just days after the president announced a ceasefire in the region.
But Sudan's armed forces denied the reports, saying they were sticking to the ceasefire. They said they had made no manoeuvres in the area.
The accusations, if confirmed, will dismay many governments and international bodies who praised Sudan's president Omar Hassan al-Bashir on Wednesday for announcing an "immediate and unconditional" end to hostilities as part of a new peace push in the western region.
Other ceasefires have fallen apart in Darfur in the past.
The reports come at a particularly sensitive time for Khartoum which has stepped up diplomatic efforts to block moves by the chief prosecutor of the International Criminal Court to indict Mr Bashir for war crimes in Darfur.
International experts say more than five years of fighting in Darfur has killed 200,000 and driven more than 2.5 million from their homes. Khartoum accuses the media of exaggerating the conflict as part of a western conspiracy against Sudan.
Commanders from four rebel factions said government Antonov planes bombed land between the settlements of Kurbia and Um Mahareik, close to a key road in north Darfur, for several hours on Friday morning.
UN sources, speaking on condition of anonymity, said they had received the same reports from rebels and civilians in the area. Many of the rebel and civilian witnesses had proved themselves reliable in the past, these sources added.
A spokesman from Sudan's armed forces said there was no truth to the reports. "Sudan's armed forces are committed to the ceasefire," he said. "The Sudanese army did not launch any air strike. The Sudanese army did not move in this area in any way."
Reuters