Bolivia's political capital, La Paz, has been gripped by demonstrations as protesters demand the nationalisation of the country's energy industry.
Farmers are demanding a new constitution and more influence
Mainly indigenous Bolivians blockaded roads into the highland city and threatened to march on Congress.
A planned session of Congress was postponed for a second day due to disagreements among lawmakers.
President Carlos Mesa has accused protest leaders behind weeks of political unrest of planning a coup.
The US State department has issued a warning to its citizens living or travelling to Bolivia about the growing unease in the country.
The latest demonstrations were far smaller than the ones which on Tuesday forced Congress to suspend its first session in over a week.
Congress was due to address the controversial issue of autonomy, a key demand of Bolivia's wealthier eastern and southern provinces which are home to most of the country's oil and gas.
The session was postponed again on Wednesday after lawmakers could not agree on an agenda for the discussions.
Police used teargas to disperse earlier protests
The BBC's South America correspondent, Elliott Gotkine, says the demonstrators - who include farmers, teachers and students - are tired of having their demands ignored and now appear to be broadening their offensive.
Major roads into the country's administrative capital were blockaded with stones.
While most demonstrations were peaceful, in some areas of the city a group of around 1,000 people smashed windows, attacked shopkeepers and vandalised cars.
The protesters, mainly from the impoverished highlands, want to stop the Congress granting autonomy to the wealthier eastern and southern provinces.
They are also demanding the nationalisation of the energy industry, saying a law which increases taxes on foreign gas investors, does not exert enough control over the country's resources.
President Mesa has said the gas law is too punishing for the multinationals that have invested billions of dollars in Bolivia's gas fields.
A similar dispute led to the overthrowing of Mr Mesa's predecessor, Gonzalo Sanchez de Lozada, in October 2003.
The president has vowed to remain in office for his full term, despite frequent political crises.
He is backed by the armed forces, which last week sacked two officers after they claimed to represent a new nationalist movement in the military.