Rival Libyan militias fired guns and rocket-propelled grenades at each other in Tripoli on Sunday and set fire to a former intelligence building, one of the worst breakdowns in security in the capital since Muammar Gaddafi's fall. At least five people were wounded and a stray bullet entered a hospital in the heart of the city, where residents rushed to arm themselves, saying calls to police had gone unheeded. After more than 12 hours, the army moved in to restore order.