Heavy fighting raged on Thursday in eastern Democratic Republic of Congo between the army and M23 rebels, who are waging their most sustained offensive since a 2012-2013 insurrection that briefly overran the major city of Goma.
The army recaptured its base in Rumangabo, the area's largest, from the M23 but the rebels still appeared to control much of the surrounding area, said Emmanuel de Merode, director of the Virunga National Park, who is based in Rumangabo.
There was also heavy fighting overnight near the strategic town of Kibumba, about 20 km (12 miles) northeast of Goma, said de Merode. An imam there said the town fell to the M23 on Wednesday.
"The army fell back, leaving the terrain to the M23. They are still there," the imam said.
It was not possible to independently verify the situation in Kibumba. Spokesmen for Congo's army could not be immediately reached for comment.
The M23 insurgency stems from the long fallout from the 1994 genocide in neighbouring Rwanda. The group's leadership is from the Tutsi ethnic group and has justified previous attacks inside Congo by saying it is battling the Democratic Forces for the Liberation of Rwanda (FDLR), a militia founded by ethnic Hutus who fled Rwanda after participating in the genocide.
In 2012, the M23 captured Goma, a city of more than 1 million people and hub for humanitarian workers, before being chased by Congolese and U.N. forces into Rwanda and Uganda the following year.
Since then, M23 fighters, frustrated by the slow pace of a demobilisation process aimed at reintegrating them into civilian life if they lay down their weapons, have periodically returned from camps in those countries to stage attacks inside Congo.
In a statement late on Wednesday, Congo's government renewed accusations that Rwanda, which is led by President Paul Kagame, a Tutsi, was backing the M23.
"The people of Kibumba ... are facing a barbarous attack by the M23 with the support of Rwanda in flagrant violation of borders and agreements signed with Congo," the statement said.
Rwanda's government spokeswoman said she would respond shortly. Rwanda has in the past denied charges it supports the M23.
A spokesman for the M23 responded to a request for comment by sending a statement decrying what it described as incitement of hatred against Tutsis in Congo.
(Additional reporting by Fiston Mahamba, David Lewis, Clement Uwiringiyimana and Aaron Ross; Writing by Aaron Ross; Editing by Estelle Shirbon)
