Bolivians demanding the nationalization of the country's energy industry have taken over several oil fields belonging to a Spanish oil company.
Officials say protesters occupied the fields near the eastern city of Santa Cruz Wednesday.
The latest protest action comes one day before legislators are scheduled to vote on whether to accept President Carlos Mesa's resignation.
President Mesa submitted his resignation Monday, saying he could no longer lead the poor Andean nation in the face of continuing large demonstrations over his government's policies.
Mr. Mesa tried to resign earlier this year, but lawmakers rejected his offer.
Thursday's special legislative session is scheduled to take place in the city of Sucre, south of the capital La Paz. The Senate president would be next in line to replace Mr. Mesa.
Some information for this report provided by AP and AFP.