KHARTOUM, Dec 5 (Reuters) - The African Union (AU) said on Tuesday it had information that its force in Darfur's main town could come under attack within 24 hours from rebels and members of a group that signed a peace deal with the Sudan government. On Monday members of a separate militia force entered El Fasher and clashed with a former rebel group which signed a peace agreement with the government in May. "Reports received earlier today from the field indicate that the city of El Fasher is under threat of attack within 24 hours by a coalition comprising the SLA (M), the G19 and the National Redemption Front (NRF)," the AU, which has a 7,000-strong force in Darfur, said in a statement. "The AMIS (African Mission in Sudan) Camp at Force Headquarters could be a target," the statement added. The SLA (M) is the military wing of the faction of the Sudan Liberation Movement that signed the peace deal. The G19 and the NRF are rebel factions which rejected the May agreement. Saif Haroun, a spokesman for the SLM, said his group had no knowledge of the possible attack. "Maybe they are elements that broke away from the movement and in that case we would not be responsible for their actions," he told Reuters. Several members have broken away from the movement in the past, frustrated with what they see as repeated delays by the government in implementing the deal. The SLM accuses Khartoum of rearming the militias, locally known as the Janjaweed, which entered El Fasher on Monday. The government says the Janjaweed are outlaws. SLM leader Minni Arcua Minnawi, now a presidential adviser, said on Monday that further attacks by the Janjaweed and the government's failure to disarm them could bring the situation in Darfur "back to square one". The AU said it had reports that two SLA soldiers were killed and three wounded in Monday's clashes in El Fasher. Two militia members were also killed, it said. The African organisation, accused of doing too little to stop the violence, said "quick intervention" by its forces prevented the clashes from escalating, adding it had also treated the wounded at its hospital. Experts say around 200,000 people have been killed and 2.5 million forced to flee their homes since the Darfur conflict flared in 2003. Rebel groups took up arms against the government, charging it with neglect. The AU agreed last week to extend the mandate of its underfunded force for six months starting January after Sudan rejected the deployment of a large United Nations force. Sudan says a U.N. force would be like a Western invasion. The AU also endorsed a proposal for a hybrid AU and U.N. force but conceded some ground to Khartoum by deciding that the U.N. should have only a supporting role.