"On Friday morning, our forces destroyed the Rokoro military garrison [in western Darfur] and took control of almost the entire region," the Sudan Liberation Movement (SLM) said in a statement.
"The movement has killed 68 enemy troops – including the region's commander, who held the rank of major – and injured more than 100 soldiers," the SLM said.
The movement went on to note that it had captured four soldiers of various ranks, while also conceding that several of its fighters had been injured in the melee.
Sudanese authorities could not be reached for comment on the SLM's assertions.
Since 2003, Darfur has been the scene of a ferocious war between the Sudanese government and three rebel movements. The conflict has left some 300,000 people dead and 2.5 million displaced, according to UN figures.
In 2009, the Darfur conflict prompted the International Criminal Court to issue an arrest warrant for Sudanese President Omar al-Bashir amid allegations that Sudanese troops and allied militias had committed atrocities in the troubled region.