LA PAZ, Bolivia - President Evo Morales struggled to assert control over a badly fractured Bolivia on Sunday as protesters set fire to a town hall and blockaded highways in opposition-controlled provinces, provoking gasoline and food shortages.
At least 30 people have been killed in the poor Andean nation this week, Interior Minister Alfredo Rada said. All the deaths occurred in Pando province, where Morales declared martial law on Friday, dispatching troops and accusing government foes of killing his supporters.
The governor of natural gas-rich Tarija, representing the four eastern provinces that are in rebellion, said before entering talks in the capital Sunday with Morales that half the country was paralyzed by 35 highway blockades.
"Also paralyzed are borders with Argentina, Brazil and Paraguay," said Gov. Mario Cossio, who expressed hope of laying the groundwork for a truce.
South America's leaders were headed to Chile, meanwhile, for an emergency summit Monday aimed at trying to prevent Bolivia from splintering apart. All the presidents of the continent's major nations except Alan Garcia of Peru confirmed their attendance, including Morales.
Government troops continued to arrive in Pando and patrol the streets of its capital, Cobija, and Morales' chief of staff, Juan Ramon Quintana, sought the arrest of provincial Gov. Leopoldo Fernandez "for violating the constitution and generating the bloody killings of the peasants."
A day earlier, Morales accused Fernandez of using Peruvian and Brazilian "assassins" in an alleged ambush of government supporters.
Vice President Alvaro Garcia announced that the national congress will begin an investigation next week of "the Pando massacre" and "the direct participation of the province's governor in that crime."
Fernandez has denied any involvement in Thursday's violence, calling it not an ambush but rather an armed clash between rival groups. On Sunday, he again disputed the government's accusations and claimed that Morales' administration was "mounting a farse."
Fernandez's security chief, Alberto Murakami, put the death toll at 15 when reached by The Associated Press by telephone.
Morales spokesman Ivan Canelas said, meanwhile, that "an armed group" set fire early Sunday to the town hall in Filadelfia, a municipality near Cobija.
"There are people who want to continue sowing pain across the region," he said.
The gravest challenge to Morales in his nearly 3-year-old tenure as Bolivia's first indigenous president stems from his struggle with the four lowland provinces where Bolivia's natural gas riches are concentrated and where his government has all but lost control. Saboteurs briefly cut some natural gas flow at midweek to Brazil, which depends on Bolivia for half its gas consumption.
The provinces are seeking greater autonomy from Morales' leftist government and are insisting he cancel a Jan. 25, 2009 referendum on a new constitution that would help him centralize power, run for a second consecutive term and transfer fallow terrain to landless peasants. Morales says the new charter is needed to empower Bolivia's poor indigenous majority.
Morales' representative in Pando, Nancy Texeira, said the death toll from Thursday's fighting between pro- and anti-government forces near the town of Porvenir was expected to rise as more dead and wounded were being found.
A peasant leader involved in the street fight told the AP in a telephone interview Saturday that the violence began after he and several truckloads of companions came upon an opposition blockade on a jungle highway.
Antonio Moreno said there was some fighting — mostly with clubs and rocks — when a man emerged from a vehicle and fired on peasants with a submachine gun.
"The campesinos fled to the mountain, while others jumped into the river," he told the AP.
Morales and his close ally President Hugo Chavez of Venezuela expelled the U.S. ambassadors in their countries last week to protest what they called Washington's inciting of the protests.
The departing U.S. ambassador to Bolivia, Philip Goldberg, denied the accusations on Sunday in his first public comments on the matter.
"I would like to say that all the accusations made against me, against the Embassy and against my nation are completely false and unjustified," he told reporters in La Paz. "I have nothing to say to those who misinterpreted my actions."
Morales has offered no detailed evidence of Goldberg's alleged conspiracy with the opposition. He has, instead, accused Goldberg of egging on anti-Morales forces through meetings with governors who have publicly called for the president's ouster.
Chavez, meanwhile, insisted he would intervene militarily in Bolivia if Morales were toppled or killed.
In a speech Saturday in Venezuela, he accused Bolivia's military brass of not fully supporting their president, of "a work stoppage of sorts."
Bolivian armed forces chief Gen. Luis Trigo earlier in the week rejected Chavez's pledge to intervene, saying no foreign troops would be permitted to set foot on Bolivian soil.
On Sunday, Defense Minister Walker San Miguel backed his armed forces chief.
"We Bolivians will resolve our problems among ourselves," he said in an interview with the state TV network.
Associated Press writers Paola Flores and Carlos Valdez in La Paz, Ian James in Caracas, Venezuela, and Frank Bajak in Bogota, Colombia, contributed to this report.