Army took control of Cobija, the capital of the northern Bolivian state of Pando, after at least 30 people died in clashes between rival groups, EFE reported on Monday quoting state television.
The army took over law enforcement and was patrolling the streets of Cobija after government declared a state of siege in Pando in the wake of armed clashes between supporters and autonomy seekers over the past week.
Supporters of autonomy in the four northern states of Pando, Santa Cruz, Tarija and Beni are demanding a greater share of revenues from oil and gas clashed with government troops.
Pando Governor Leopoldo Fernandez and the federal government accused each other of inciting the violence.
The four northern states have been demanding the restoration of the 30-percent local share of the tax on hydrocarbons, which President Evo Morales diverted to pay for his social agenda for the country's poor.
Morales said he was willing to discuss the tax issues and proposed constitutional amendments regarding regional autonomy.
Meanwhile, the opposition parties supporting the autonomy demand of the southern provinces said on Sunday they would lift the highway blockades as a "goodwill gesture" to help in resolving the crisis.