Rebels in Sudan's Darfur region are accusing the government of attacking them in western Jebel Marra.
A government military spokesman confirmed to the Reuters news agency that government forces fought with Southern Liberation Army rebels on Sunday, with both sides suffering casualties.
Reuters quotes an SLA spokesman as saying that 19 civilians were killed while some some 10,000 others fled during the fighting which the government spokesman denied.
Rebels in Darfur took up arms against the government of President Omar al-Bashir in 2003. The United Nations says more than 300,000 people have been killed in the conflict, and 2.7 million others displaced.