GOMA, Congo — Rwandan support for rebels in neighboring Congo has waned but not ended in the past six months, according to a United Nations group of experts report.

In their mid-year report to the U.N. Security Council's Congo sanctions committee that became public Saturday, the group says the M23 rebel movement has continued recruiting in Rwanda "thanks to assistance from some sympathetic Rwandan officials." Some M23 deserters who fled to Rwanda also have been sent back to the rebels, it said.

But the group also reports "no evidence of full Rwandan army units supporting M23" since November when the rebels briefly occupied Goma, one of eastern Congo's biggest cities.

In 2012, the group of experts alleged that Rwanda's defense minister had been commanding the rebellion and that Rwandan army units had supported M23 at critical stages. Rwanda's government has vigorously denied the accusations.

The experts' latest findings suggest that insurgents in Congo are collaborating with the Congolese military as well as with Rwandan officials.

They report "enhanced collaboration" since November between some FARDC (Congolese army) units and the FDLR (Rwandan rebel Democratic Forces for the Liberation of Rwanda) in areas close to the M23.

In the past Rwanda has justified military intervention in Congo to protect itself against the FDLR, some of whose core members took part in the Rwandan genocide in 1994.

The experts say they have written to the governments of Rwanda and Congo asking for clarification about the reports of support to M23 and collaboration with FDLR and are awaiting replies.

The report found that M23 has been weakened weakened after fighting between rival factions, led by Bosco Ntaganda and Sultani Makenga.

Ntaganda's forces ran out of ammunition and fled to Rwanda where their leader handed himself in at the U.S. Embassy in March, asking to be transferred to the International Criminal Court which had issued a warrant for his arrest.

The experts say a majority of M23 combatants supported Ntaganda. His defeat, they say, has left the movement low on men and morale, and less able to raise recruits and funds after losing the support of Ntaganda's clan network.

"M23's failed attempt at the end of May 2013 to recover a key FARDC position near Goma illustrates the movement's current inability to carry out large-scale coordinated military operations," the report says.

It cites M23 deserters as saying that despite that defeat Makenga is preparing further operations against Goma.

The large United Nations peacekeeping force in the Congo, MONUSCO, is being reinforced by an intervention brigade of 3,000 troops with an offensive mandate to neutralize armed groups. Most of this force has now arrived in the Goma area.

It is not expected to take immediate action against the M23, which is in peace talks with the Congolese government in Kampala. Local observers say Congolese armed groups that recently reoccupied towns in Masisi, a territory close to Goma, could be the brigade's first target.