Protests against a sharp increase in fuel prices intensified and turned violent in Bolivia, as thousands of demonstrators demanded President Evo Morales' government repeal the hike.
Demonstrators filled the streets in La Paz and other cities to protest the higher prices, which were announced suddenly on Sunday.
Petrol prices immediately soared by 73% and diesel prices went up by 83%, leading to a rapid increases in transport and food prices in the Andean country.
Some demanded the resignation of Mr Morales, a close ally of Venezuelan President Hugo Chavez. It has been the most unpopular measure of Mr Morales' five-year presidency.
Taxi drivers held a strike that largely paralysed La Paz, and protests were also held in the cities of Cochabamba, Santa Cruz, Potosi and Oruro.
The march in the capital began peacefully but clashes with police erupted when demonstrators tried to enter the main plaza where the government palace is located.
Police used tear gas to disperse the protesters, who hurled stones at officers, the vice presidential office, a union headquarters and two ministry buildings. In El Alto, a city neighbouring the capital, demonstrators torched a car and toll booths. People lined a bridge while protesters raised fists demanding the measure be repealed.
Interior Minister Sacha Llorenti said disturbances in La Paz, El Alto and Cochabamba left 15 police officers injured, two seriously. A group of protesters burned a Venezuelan flag.
Fuel prices had been frozen for six years, but the government said it could no longer afford to subsidise them, especially since much is smuggled across the border to neighbouring countries.
Responding to the protests, Mr Morales' government has announced steps aimed at mitigating the economic effects - including 20% salary increases for public workers aimed at offsetting higher fuel prices. The government also announced new assistance to rice, corn and wheat farmers intended to increase production and bring down prices.