Belfast, Northern Ireland ? A major outlawed Protestant group in Northern Ireland has abandoned its 11-year-old truce and is an enemy of the peace once again, Britain declared today in a long-expected verdict against the Ulster Volunteer Force.

The British governor, Peter Hain, said he has received sufficient evidence that the UVF – an underground group supposed to be bolstering Northern Ireland’s Good Friday peace accord with a 1994 cease-fire – committed four killings this summer and launched multiple gun and grenade attacks this week against the police and British army.

Hain’s Northern Ireland Office said in a statement that UVF members’ violence “amounted to a breakdown in their cease-fire” and meant that, as of midnight, Britain no longer accepted it as valid.

The move followed three nights of Protestant riots that ravaged much of Belfast and other Northern Ireland towns.

Police commanders said the UVF and a larger Protestant paramilitary group, the Ulster Defense Assn., both attacked police and British troops with assault-rifle fire and homemade grenades in what have been the worst Protestant riots for nearly a decade.

But Hain said Britain would continue to recognize the validity of the UDA’s own 1994 cease-fire, partly because that group has not been linked to any recent killings.

The rioting, which exploded each night from Saturday to Tuesday morning, left at least 60 police officers and several dozen civilians wounded, none fatally. The trigger – British authorities’ refusal Saturday to allow Protestants to parade along the edge of Catholic west Belfast – capped years of growing Protestant opposition to the landmark 1998 peace accord.