By Joe Bavier
KINSHASA, Jan 28 (Reuters) - Congolese Tutsi rebels and Mai Mai militia clashed on Monday in eastern Democratic Republic of Congo, breaking a ceasefire signed last week aimed at ending a long-running conflict, the two factions said.
Tutsi fighters loyal to renegade General Laurent Nkunda and Pareco Mai Mai militia, who both signed a peace accord on Wednesday, blamed each other for the fighting around villages 70 km (44 miles) west of the town of Goma.
No details of casualties were immediately available and the U.N. peacekeeping mission in Congo said it could not confirm who had attacked first.
Nkunda's rebel National Congress for the Defence of the People (CNDP) and the Pareco Mai Mai faction were among 25 armed groups that agreed to an immediate ceasefire in Wednesday's accord, which was also signed by the Congolese government.
The United Nations and Western governments were hoping the pact, which followed more the two weeks of talks, would end conflict in eastern North and South Kivu provinces which has persisted despite the formal end of Congo's 1998-2003 war.
The latest fighting broke out near the villages of Lusirandaka and Kasake at dawn on Monday.
"This is a serious violation of the ceasefire that we've just signed," Seraphin Mirindi, a military spokesman for Nkunda, told Reuters.
"Pareco and FDLR (Rwandan Hutu rebels) tried to attack our soldiers. They even took some positions before we pushed them back."
Pareco Mai Mai spokesman Theophile Museveni blamed the attack on Nkunda's CNDP.
"We signed (Wednesday's accord), and we respect our commitment. But if the CNDP do not respect what they signed, if they say they do not want peace, and if (the U.N.) does not want to react, we will have to defend ourselves," he said.
BUFFER ZONES
As part of the ceasefire, peacekeepers of the 17,000-strong U.N. contingent in Congo have been deployed to create buffer zones between the rival eastern factions.
Long after the wider 1998-2003 war ended, fighting has raged on in the east, adding to a humanitarian catastrophe that has caused more deaths -- 5.4 million since 1998 -- than any other conflict since World War Two, relief experts say.
Although Wednesday's deal raised peace hopes, political analysts said its implementation, including the creation of a military technical commission to monitor the ceasefire, could still create problems.
"Getting the technical commission up and running is essential to the success of the peace agreement," Anneke Van Woudenberg, a senior researcher in Congo for New York-based Human Rights Watch, told Reuters.
"Without it, the deal is just a piece of paper with no ability to monitor the ceasefire."
The accord offers a limited amnesty covering acts of war and insurgency to the rebel and militia fighters involved. It does not cover war crimes, crimes against humanity or genocide.
Officials said last week Nkunda could win amnesty under the accord and Congo's government had not renewed an arrest warrant against him for war crimes.
(Editing by Pascal Fletcher and Andrew Dobbie)