The government immediately ordered additional troops to Bolivia's rebellious eastern provinces to secure gas and oil installations. Ramirez said both gas plants remained occupied by protesters on Wednesday afternoon.

A Bolivian a protester carries riot control weapons that were taken from the police during a strike in Santa Cruz September 9, 2008. Hundreds of autonomy activists clashed with riot military forces during a protest against President Evo Morales' policies. [Agencies]

The pipeline blast reduced by 3 million cubic meters the 30 million of gas Bolivia sends Brazil each day, he said. But in Brazil, officials said the gas flow remained normal.

Brazil's ambassador to Bolivia, Frederico Araujo, was quoted by the government's official news service as saying Brazil would not be affected for 48 hours.

"They damaged only one valve, they didn't explode the pipeline like it's been said in the news," Agencia Brasil quoted him as saying. Bolivia supplies neighboring Brazil with 50 percent of its natural gas, used for power generation and as fuel for cars and cooking.

Ramirez said it would take 15 to 20 days to repair the pipeline at a cost of US$100 million. He said Bolivia would lose US$8 million a day in revenues.

Morales' opponents in the east are seeking a greater share of revenues from natural gas, Bolivia's chief export, for the richer lowland provinces, home to the bulk of its gas fields.

Morales has devoted much of those revenues to programs that benefit the poor and elderly. He has called the protests a "civil coup."

Opposition leader Branko Marinkovic, the owner of large land holdings in soy-growing Santa Cruz, said Tuesday that the only way out of the conflict is for the government to cancel a December 7 referendum on a new constitution.

The proposed new constitution, which would give indigenous groups greater control of their traditional lands and make it easier for the government to redistribute fallow land, was approved by a special assembly last year amid an opposition boycott.