BY ALVARO ZUAZO
Associated Press

LA PAZ, Bolivia - An angry miner with dynamite strapped to his chest blew himself up inside Bolivia's congress Tuesday, also killing two police officers, authorities said.

La Paz Police Chief Guido Arandia said the man -- whose demand for early retirement benefits underscored the grievances of many low-paid miners in Bolivia -- stormed into congress around midday and went to a part of the building away from the congressional chambers.

The miner detonated his vest laced with at least five sticks of dynamite as congressional security police tried to negotiate, killing himself and fatally wounding two of the police, Arandia said.

Police had evacuated Congress earlier Tuesday after receiving reports that disgruntled miners planned to force their way into the building. Police had no immediate report on whether the bomber was acting alone or with others.

The bombing comes with thousands of Bolivian miners out of work. In recent years the government has opened the country's vast reserves of gold and other mineral deposits to private mining companies.

In October, disgruntled miners joined with indigenous groups and labor organizations in leading days of violent protests against then-President Gonzalo Sánchez de Losada. Rioting killed at least 58 people and was sparked by the president's unpopular plan to export natural gas.

President Carlos Mesa has worked to ease still-simmering social tensions among the majority poor in this country of 8.2 million. But he continues to face pressure from the protest groups to turn around a slumping economy and narrow the gap between rich and poor.