Thousands of Catholics rioted across Northern Ireland early Tuesday, hurling firebombs and torching cars in anti-British protests hours after suspected Protestant gunmen killed two Catholics in a new round of sectarian violence.

"All hell is breaking loose," said one Belfast resident as police and witnesses reported major disturbances in at least a dozen towns.At least three people were reported missing after their car was forced to a stop by a burning barricade in an Irish Republican Army stronghold, and they were pulled from their vehicle, authorities said.