Hundreds of angry Shi'ite Muslims protested electricity rationing by blocking some major roads in Beirut and its southern suburbs Sunday, forcing Lebanese troops to intervene, security officials said. Three people were reported killed and 10 wounded. The riots started in the afternoon when some 50 government opposition supporters set tires on fire closing the Mar Mikhael intersection, which is a major link between different areas of Beirut, said the security officials, who spoke on condition of anonymity because they were not allowed to speak to the media. Scores of troops arrived shortly afterward and opened fire in the air to disperse the demonstrators, they said. Two people, one of them an official with the Shi'ite Amal group, were killed on the spot in the shooting near Mar Mikhael while the third died of his wounds at a hospital in southern Beirut, the officials said. Ten people were wounded, they said.