Northern Ireland's welfare system was virtually shut down for a day when Irish nationalist guerrillas, angered by a crackdown on welfare fraud, issued death threats against investigators, and welfare workers responded with a protest strike.

The death threats followed by the strike Tuesday endangering payments to 200,000 people so alienated the public that the Irish nationalists were forced to withdraw their death threats.

Welfare offices were expected to reopen Wednesday.

"It just goes to show that no matter how dedicated the guerrillas are, they have no chance when they take action that could halt the dole," one Belfast analyst said.