Updated

Rwanda's military is providing weapons and refuge to an ex-warlord indicted for war crimes and whose fighters have launched a new rebellion in neighboring eastern Congo, an international human rights group said Monday.

The International Criminal Court has sought the arrest of Bosco Ntaganda for years, though Congo's government had allowed him to operate freely as a general in its army, only recently vowing to capture him.

Human Rights Watch said Monday it also had evidence that Ntaganda and his supporters were evading capture with the help of the Rwandan military. The renegade general is believed to have been born in Rwanda and has close ties there.

The New York-based group said Rwandan military officials had given Ntaganda's fighters machine guns and grenades, breaking a U.N. embargo. The group also said Rwandan army officials had provided up to 300 fighters, some of whom had been forcibly recruited.

"Arming Ntaganda enables further grave abuses by a man already wanted for war crimes," said Anneke Van Woudenberg, senior Africa researcher at Human Rights Watch. "The Rwandan government should investigate the serious allegations of support for Ntaganda by its military officials and help the Congolese government arrest and transfer him to the ICC."

The Rwandan government has denied any involvement in the rebellion that has further destabilized a region long in turmoil.

Last week, Rwanda's Foreign Minister Louise Mushikiwabo dismissed claims that Rwandans recruited and trained for the Rwandan army have been transferred to eastern Congo to fight for the rebels, as "categorically false and dangerous."

Eastern Congo has been engulfed in fighting since the 1994 Rwanda genocide, in which at least 500,000 Tutsis and moderate Hutus were slaughtered by Hutu militias before a Tutsi-led rebel army took power in Rwanda.

More than 1 million Rwandan Hutus fled across the border into Congo, and Rwanda has invaded Congo to take action against Hutu militias there.

Ntaganda, who is a Tutsi, was once a feared warlord until he joined the Congolese army in 2009 as a general following a peace deal that paved the way for him and his men to be integrated into the military.

He was allowed to live freely in the provincial capital of Goma, where he played tennis and dined at top restaurants despite an International Criminal Court indictment for war crimes allegedly committed by troops under his command, including the forced recruitment of children.

In April, however, the agreement between the former warlord and the Congolese government disintegrated, and he and his troops defected.

The Congolese government has said that it believes Ntaganda to be the force behind a new rebel group known as M23. However, the group has said that theirs is a separate rebellion and Ntaganda is not with them, a claim that is countered by some who defected and later spoke to Human Rights Watch investigators.

Ntaganda's whereabouts are unknown, though Human Rights Watch said witnesses report spotting him meeting with a Rwandan military officer inside Rwanda. Ntaganda is on a U.N. Security Council sanctions list, which should bar him from travel outside Congo.