In pictures: Behind Congo's rebel lines

Government forces are trying to crush various rebel groups in eastern Democratic Republic of Congo. The BBC's Thomas Fessy went to one of the frontlines in Lukweti, 100km (60 miles) north-west of Goma.

The Lukweti area is very remote - the rains make roads impassable. It is the stronghold of local Mai Mai militias, who are refusing to join the army as agreed in a peace deal earlier this year.

The UN peacekeeping mission, Monuc, has not been able to penetrate the area either. The blue helmets face hostility as they backed a government operation with attack helicopters in September.

General Janvier Bwingo Karairi leads the area's main Mai Mai group, made up of mainly ethnic Hundes. He says he pulled out of the deal as ethnic Tutsi rebels, who he had been fighting, were given prominent army positions.

rebel commanders from APCLS and FDLR in Mandimu village

Gen Janvier, who gained power over Lukweti this year, says his group was marginalised. He has strong support from the local population. His fighters, estimated at between 1,000 and 1,500, are well equipped and organised.

General Janvier's fighters share information with their counterparts – ethnic Hutu Rwandan rebels from the FDLR movement. Together they have resisted the national army for the past eight months.

FDLR rebels have been at the heart of years of unrest in the region. The group has better communication equipment and so receive constant updates on the situation. Child soldiers are visible in both groups.

This FDLR fighter - barely a teen - was wounded by a bullet during combat. Unlike the Mai Mai, the FDLR do not believe that evoking their ancestors by spraying water or wearing leaves protects them while fighting.

These people were forced to flee the fighting, south of Lukweti village. They said they tried to pass through the Congolese army's positions but turned back after soldiers started looting.

dead FDLR rebel being carried on a stretcher

The FDLR, some of whose leaders were involved in the 1994 genocide in Rwanda, have been active in the region for a decade. This FDLR fighter was killed in heavy fighting and was buried by his comrades the next morning.

Humanitarian problems arising from the continuing military action is causing the UN deep concern. Monuc wants to establish a base in Lukweti but so far Gen Janvier has not agreed. [Photos and text: BBC's Thomas Fessy]