Acts of violence on the streets of Santa Cruz, Bolivia
Anti-government protesters in Bolivia have clashed with supporters of leftist President Evo Morales, during a general strike against his policies.
Hundreds of police officers took to the streets of the city of Santa Cruz to break up violent confrontations.
Activists in five of Bolivia's nine regions went on strike, protesting over Mr Morales's plans to share natural gas revenues with poorer provinces.
The five energy-rich provinces have called for more autonomy from La Paz.
The organisers of the strike said it would be followed on Wednesday by a day of roadblocks to cut off access to those regions.
The bubbling crisis led to a national referendum on the positions of Mr Morales and the governors of the five eastern provinces opposed to him.
Voters gave overwhelming backing to Mr Morales in the 10 August ballot.
But they also approved the opposition governors - doing nothing to ease the political deadlock.
Police fired tear gas into the crowds during clashes in Santa Cruz, the nation's business capital.
Anti-government demonstrators carrying baseball bats and shields fought with Morales supporters in a poor neighbourhood of the city.
Local television showed pictures of youths clashing with police and journalists in other parts of the city.
In Tarija, the province holding much of the country's natural gas reserves, a small group of protesters was reported to have stormed and occupied a government building.
One-day strikes were held in Santa Cruz, Beni, Pando, Tarija and Chuquisaca provinces.
Bolivia's four other provinces, where Mr Morales enjoys huge popularity, did not hold strikes.
The governors of the five provinces opposed to Mr Morales want him to stop taking energy revenues previously earmarked for their provinces to pay for a national pension scheme.
But he argues that they can afford to help with anti-poverty programmes because their coffers swelled after he increased taxes on energy companies in 2006.
Repeated attempts at dialogue between the government and the governors have failed to produce any agreement.
The strikes are another indication that the current deadlock is no nearer a solution, says the BBC's Latin America analyst James Painter.
Concern is growing that without compromise by both sides, Bolivia will be trapped in a debilitating crisis, our correspondent adds.
The latest violence comes just days after another anti-Morales march in Santa Cruz saw police fire tear gas at protesters.
The province's governor, Ruben Costas, said the president was responsible for the clashes, accusing him of being "the real criminal".