(Adds U.N. statement, paragraphs 9-11) By Joe Bavier KINSHASA, Feb 22 (Reuters) - A month-old peace accord in east Democratic Republic of Congo faced a fresh hitch on Friday when Tutsi rebels halted participation in a ceasefire commission in protest at U.N. allegations they had massacred civilians. The move announced by renegade Tutsi General Laurent Nkunda posed a potential threat to the Jan. 23 ceasefire and peace pact signed by Nkunda's rebels, Congolese President Joseph Kabila's government and rival eastern militia groups. The United Nations and Western governments brokered the deal in the hope of establishing a lasting peace in Congo's turbulent east, where rebel and militia violence has persisted long after the formal end of a 1998-2003 war in the central African state. Nkunda denied allegations by U.N. investigators that his Tutsi fighters killed at least 30 Hutu civilians last month while his rebel group negotiated the peace deal, which has already been strained by renewed skirmishes in the east. "We are demanding these things be verified by a mixed investigation made up of the government, the U.N., and us," Nkunda told Reuters, dismissing the allegations as "rumours". Nkunda said that until an independent inquiry was launched, his representatives were suspending their participation in an ad hoc commission tasked with sorting out aspects of the ceasefire. But a rebel spokesman said this did not mean that Nkunda's National Congress for the Defence of the People (CNDP) insurgent group was withdrawing from the ceasefire accord. "It's a setback but not a mortal wound to the peace process," one diplomat said, asking not to be named. The U.N. mission in Congo (MONUC), which has 17,000 peacekeepers in the former Belgian colony, encouraged the CNDP to continue working for peace but defended its statement and said it would cooperate with any independent inquiry. "The MONUC investigation of these killings was conducted with professional care and its findings reflect credible information received from a number of eye witnesses and other sources," it said. "The mission believes any other independent and impartial inquiry will confirm the outcome of the investigation." CALL FOR RIGHTS RAPPORTEUR The U.N. rights investigators' report, which became public this week, alleged that Tutsi fighters loyal to Nkunda shot, hacked with machetes, or beat to death with hammers at least 30 Hutu civilians on Jan. 16 and 17 around Kalonge, around 100 km (64 miles) west of Goma, capital of east North Kivu province. Nearly all the victims were men, though a one-year-old baby, a 14-year-old boy, and a woman were also killed. Rights groups have accused all warring parties in North Kivu's conflict of committing rapes and killings over the years. Human Rights Watch called for a special rapporteur to follow up on commitments made by those who signed the Goma deal. While announcing its withdrawal from "all meetings relating to the Act of Engagement", as the Jan. 23 deal is known, the rebel CNDP said nevertheless it was willing to cooperate with international mediators to clear up the massacre allegations. But it said the allegations made by the U.N. investigators infringed MONUC's role as a mediator in the peace process. Despite the creation of around 30 U.N. peacekeeping bases in a buffer zone between the warring factions, almost daily clashes have been reported between Nkunda loyalists and Mai Mai militia. Some 450,000 North Kivu residents fled fighting in the province in the year leading up to last month's peace deal. The conflict has its roots in neighbouring Rwanda's 1994 genocide in which around 800,000 Tutsis and moderate Hutus were slaughtered. Nkunda says the rebellion he has led since 2004 seeks to protect east Congo's ethnic Tutsi minority against the Rwandan Hutu rebels he says are backed by Congo's government. (Editing by Pascal Fletcher; Editing by Caroline Drees)
