The militiamen first entered Kananga and continued attacks on Friday, including against the town airport.
The death toll from militia clashes with security forces in the Democratic Republic of Congo last week was at least 49, more than three times the number earlier reported, the governor of the province hit by the violence was quoted on Monday as saying.
Fighters from militia group Kamwina Nsapu, seeking to avenge the death of their leader of the same name, battled security forces on Thursday and Friday in the town of Kananga in the centre of the vast central African country.
U.N.-funded Radio Okapi quoted Alex Kande, governor of Kasai Central province as saying that 27 of the dead were militiamen, 16 were members of the security forces and six were civilians.
Initial estimates had put the toll at 13.
The militiamen first entered Kananga on Thursday morning and continued attacks on Friday, including against the town airport.
Tensions between local authorities and Kamwina Nsapu, whose men are often armed with little more than clubs and magic amulets, has erupted into deadly violence on several occasions.
A decade after the end of a 1996-2003 regional war in Congo that killed millions, the mineral-rich country remains a tinderbox of armed groups and ethnic militias.