One of Democratic Republic of Congo's most senior army commanders has been selling weapons to rebel groups accused of carrying out widespread massacres, according to a UN report.
The report claims that General Gabriel Amisi, a Congo land forces commander who was driven out of the eastern city of Goma by M23 fighters on Tuesday, oversaw a network providing arms and ammunition to criminal groups and rebels from Congo's troubled east.
The M23 rebel group that seized Goma, however, was not among the armed bands named in the UN report as receiving weapons through the network.
"General Gabriel Amisi oversees a network distributing hunting ammunition for poachers and armed groups, including Raia Mutomboki," the report said in reference to a local militia accused of widespread atrocities.
The report also said that Amisi ordered that 300 AK-47 assault rifles be given to another armed group operating in eastern Congo, known as Nyatura.
Earlier this month a separate UN investigation said Raia Mutomboki and Nyatura, along with the Rwandan FDLR rebel group, had been responsible for the deaths of more than 260 civilians in a wave of tit-for-tat ethnic massacres in remote parts of North Kivu province.
According to the report by the so-called Group of Experts, ammunition is bought in neighbouring Congo Brazzaville, before being smuggled through the Congolese capital Kinshasa to the east by a close network of Amisi's associates, including members of his family.
In separate development, the UN defended its failed effort to prevent rebels from seizing Goma, saying on Wednesday its helicopters had fired hundreds of rockets at rebels but were unable to beat them back as their ranks swelled.
Goma is a regional headquarters of a UN force, known as MONUSCO, tasked with assisting government troops to protect civilians, but peacekeepers largely looked on once the army fled and the city fell.
"Clearly, it is not the mandate of MONUSCO to directly hit the armed groups ... They have to be in support of the armed forces of Congo," UN peacekeeping chief Herve Ladsous told reporters at the UN.
"That is hardly achievable in a situation when there is no FARDC [Congo army] to support."
France called the failure of the peacekeeping force, which has heavy weapons and helicopters, to halt the advance of the lightly-armed rebels "absurd," and said its mandate should be reviewed.
Roger Meece, head of the UN mission in Congo, briefed the Security Council on Wednesday by video link from Kinshasa, and said the rebels has shown renewed capacity and sophisticated tactics as they advanced on Goma over the weekend.
While UN officials have said M23 were not engaging UN peacekeepers now, Meece said the United Nations had been the target of Congolese protesters.
"Since the occupation of Goma by the M23 we find there are violent protests and spontaneous demonstrations aimed at symbols of power in the Congo as well as UN staff and facilities," he said.
"The risk of seeing this spread to other cities in the Congo is not to be excluded."
UN helicopter gunships flew 17 sorties, firing 500 rockets and four missiles in the defence of Goma, the UN said in a statement on Wednesday giving its account of the battle. Two South African peacekeepers were injured.
About 500 rebels made an initial advance on November 15. About 64 rebels were killed by army forces backed by UN helicopter gunships, it said. But two days later, the rebels returned in far greater numbers, launching a new attack with 3,000 men.
The UN Security Council has expressed "concern at reports indicating that external support continues to be provided to the M23, including through troop reinforcement, tactical advice and the supply of equipment," but did not name Rwanda.
The rebellion was launched eight months ago by mutinous troops accusing the government of failing to stick to a 2009 deal with insurgents to end a previous conflict. On Wednesday they said their aim was to "liberate" the country.