The bodies of about 160 Congolese Tutsis killed in Burundi during the weekend were buried on Monday, but the impact of the massacre is just beginning to be felt. A former rebel group now in the transitional government in the Democratic Republic of Congo has returned to its base and called for a break in the peace process.

Although it is still not exactly clear who was responsible, the political fallout of last week's massacre of Congolese Tutsis is beginning to be felt in Africa's troubled Great Lakes Region.

During the burial service in Bujumbura and speaking to U.N. radio later in the day, Azarius Ruberwa, the head of the former rebel group RCD-Goma and now one of Congo's vice presidents, said the Congolese peace process had broken down.

Mr. Ruberwa added that, in the light of the massacre, which he called genocide, there was a need to have a pause in the transition, reread the agreements that the belligerents signed and reflect on the state of the peace process.

The comments were followed by an announcement that all the senior RCD-Goma leaders were returning Tuesday to their traditional base in Goma, in eastern Congo, where they would analyze the transition.

RCD-Goma stopped short of saying it was pulling out of the transitional government, but analysts and diplomats in Kinshasa fear that the meetings in Goma may lead to their doing so. The government was set up to lead Congo to elections in 2005, following the official end of a five-year war that involved six neighboring countries and killed three million people.

But the former warring factions have remained deeply divided, most of the important reforms that are intended to help rebuild and unify the war-torn country have not been implemented, and frustrations have been building in recent months.

A government spokesman recognized the threat posed by the latest developments, but he accused RCD-Goma of implementing a long-standing plan to destabilize the peace process.

He said the party was manipulating the deaths of the Congolese Tutsis to justify its withdrawal from the transitional government.