Congolese troops killed 36 Burundian rebels in clashes with two armed groups in the east of Democratic Republic of Congo (DRC) and three soldiers were also killed, the DRC army said on Friday.

The Congolese army mounted a series of operations between April 6 and 8 in the eastern province of South Kivu aimed at regaining territory from the Burundian rebel groups National Liberation Forces (FNL) and the Burundian Republican Forces (FOREBU).

"During the three days of combat, 36 of these rebels have been neutralised," army spokesperson Dieudonne Kasereka said.

FNL leader general Aloyse Zabampema was seriously wounded, he said. Several areas formerly under the control of rebels have been recovered by Congolese soldiers, he added.

Reuters was unable to immediately confirm the army report.

The FNL is among several ethnic Hutu rebel groups that rose up to fight Burundi's Tutsi-led military government in the 1993-2005 civil war. Though it officially disarmed in 2009, pockets of FNL fighters remain active in eastern Congo.

Millions were killed in the civil war in Congo between 1998-2003, when foreign armies and allied rebel groups clashed over territory and mineral concessions, mostly in the east.

Congo's President Felix Tshisekedi, who took office in January, has pledged to address the militia violence that persists in the region.