Anti-government protesters fought backers of President Evo Morales on Thursday in Bolivia's pro-autonomy east with clubs, machetes and guns and seized more natural gas fields.
At least eight people were killed and 20 injured in street fights, authorities reported.
Meanwhile, U.S. officials angered by Morales' decision to expel Washington's ambassador responded Thursday by kicking out Bolivia's top diplomat.
On Thursday night, Venezuelan President Hugo Chavez said the U.S. ambassador to his country had 72 hours to leave and that he was recalling his ambassador from Washington. Chavez said he was asking U.S. Ambassador Patrick Duddy to leave in part to show solidarity with Morales.
Half of Bolivia's natural gas exports to Brazil — its No. 1 customer — were halted for nearly seven hours on Thursday because of sabotage by anti-Morales activists, according to the affected Transierra pipeline company.
Protesters also stormed the Pocitos gas installation that supplies neighboring Argentina. Plant technicians shut off gas to the country as a precautionary measure, an engineer at Pocitos told The Associated Press.
However, an executive with Transportadora Gas del Norte, the Argentine pipeline company that receives the Bolivian gas, told the AP that the gas flow was unaffected Thursday.
Both officials spoke on condition of anonymity, saying they were not authorized to comment on the matter.
Bolivia's finance minister, meanwhile, said gas deliveries to Brazil would be curtailed by 10 percent for up to two weeks as workers fix a pipeline ruptured by protesters on Wednesday. Bolivia supplies Brazil with 50 percent of its natural gas.
A two-week protest against Morales' plans to redo the constitution and redirect gas revenues turned violent this week as demonstrators in the country's energy-rich eastern provinces stormed public offices, blocked roads and seized gas fields.
Opposition groups in the provinces — Santa Cruz, Beni, Pando and Tarija — are fighting Morales' leftist government for control of Bolivia's lucrative gas revenues.
They also are demanding he cancel a Dec. 7 nationwide vote on a new constitution that would help him centralize power, run for a second consecutive term and transfer fallow terrain to landless peasants from Bolivia's poor indigenous majority.
"We're going to tolerate only so much. Patience has its limits," Morales told supporters on Thursday. The Aymara Indian and former coca growers' union leader has so far hesitated to mobilize the military, fearing major bloodshed.
The eight deaths Thursday occurred in Pando outside the capital, Cobija, in a rumble between pro- and anti-government bands in a jungle region, Sacha Llorenti, a deputy minister for social movements, told the AP.
Presidential spokeswoman Nancy Teixera said at least 20 people were injured. Radio reports said the groups fought with clubs, machetes and shotguns. Interior Minister Alfredo Rada confirmed the use of firearms.
About 80 people were hurt in another clash late Wednesday in the natural gas-rich province of Tarija where the gas fields were seized, according to police and media reports.
The protests forced the closure of various regional airports, and American Airlines canceled all flights to Bolivia through Saturday. Company spokeswoman Martha Pantin said it expected flights to resume beginning Sunday.
In Washington, the Bush administration Thursday ordered the expulsion of Bolivia's ambassador to the U.S. after Bolivia expelled the U.S. envoy there, the State Department said.
"In response to unwarranted actions and in accordance with the Vienna Convention (on diplomatic protocol), we have officially informed the government of Bolivia of our decision to declare Ambassador Gustavo Guzman persona non grata," spokesman Sean McCormack said.
It was unclear exactly how long Guzman would have to leave the United States but diplomats declared "persona non grata" are generally given 72 hours to depart. Guzman had been summoned to the department earlier Thursday and told of the decision a day after Bolivia expelled U.S. Ambassador Philip Goldberg, officials said.
Morales had ordered Goldberg out, accusing him of conspiring with Bolivia's conservative opposition. McCormack called that a "grave error."
Bolivian Foreign Minister David Choquehuanca told reporters Thursday that he had formally requested Goldberg's expulsion but added that he also wrote U.S. Secretary of State Condoleezza Rice, saying Bolivia "wishes to maintain bilateral relations."
In Venezuela on Thursday, President Hugo Chavez threatened military intervention if his ally Morales were to be overthrown: "It would give us a green light to begin whatever operations are necessary to restore the people's power."