A Bolivian miner has blown himself up at the national Congress building in La Paz, in a protest over his pension.
Congress had been evacuated before the bomb went off
Eustaquio Picachuri, aged 47, also killed two security officers and wounded several others.
The man was reportedly negotiating with the Congress's security team when he set off dynamite strapped to his body.
The incident comes as President Carlos Mesa tries to ease tensions in Bolivia after October's national protests by farmers, workers and miners.
Mr Mesa left the building shortly before the explosion, which happened while Congress was sitting.
The building had been evacuated and sessions were immediately suspended.
Mr Mesa described the attack as an isolated incident and called for calm.
The miner was "in an apparent state of desperation"
, he added, in remarks reported by Reuters news agency.
The bombing comes at a time when thousands of Bolivian miners are out of
In recent years the government has opened the
country's reserves of gold and other mineral deposits
to private mining companies.
In October, miners, farmers and workers took part in protests sparked by President Gonzalo Sanchez de Lozada's plan to export natural gas.
Dozens died in the protests that led to the president's resignation.
Since taking office, Mr Mesa has worked to ease
social tensions in one of the poorest countries in Latin America.
But he continues to face
pressure from the protest groups to turn around a slumping
economy and narrow the gap between rich and poor.