Police in the capital, La Paz, said on Tuesday, the man set off dynamite strapped to his body in a building annexed to the main congressional building.

President Carlos Mesa said the bombing stemmed from a personal grievance and was not part of a larger plot.

"It was a regrettable, isolated incident, without any political implications," Mesa said. The president said the miner was "in an apparent state of desperation".

The blast in a building next to the main legislative building killed Colonel Marvel Flores, head of security for the Congress, and another police officer, said Raul Moreno, sergeant at arms.

Several of those wounded were among those who tried to prevent the attack, officials said.

The miner, identified as Eustaquio Pichacui, was stopped when he tried to enter the main Congress building to demand that the government return tax money taken for his retirement.

Chamber evacuated

The speaker of the Chamber of Deputies, Oscar Arrien, reportedly halted work and ordered the chamber to be evacuated moments before the blast.

"We have received anonymous threats for some time, but this is going too far," said Elsa Guevara Aguirre, deputy speaker of Bolivia's Congress.

"This is an attempt to force us to break with democracy. We Bolivians have not opted for death but to live in peace, liberty and democracy," said Guevara, who is with the Revolutionary Left Movement (MIR).

The incident came as President Mesa tries to ease tensions in Bolivia after October's deadly national revolt by farmers, workers and miners. Dozens of poor Indians died in the revolt that led to the ousting of President Gonzalo Sanchez de Lozada.