The leaders of Venezuela and Argentina cancelled a trip to Bolivia after two people were killed and many were injured during protests across the country before a recall vote facing President Evo Morales.
Dozens of protesters tried to storm the main airport in Tarija in southern Bolivia, forcing Venezuelan President Hugo Chavez and Argentine President Cristina Fernandez to call off a trip to the area, which is rich in natural gas, for energy talks with Morales.
The two deaths and many injuries, occurred in clashes between police and workers near Bolivia's largest tin mine, Huanuni, where miners are demanding higher pensions.
The government said both the Huanuni miners' and the anti-Morales protests were attempts by the opposition to weaken the president before a recall vote on Sunday that will either ratify him or force him out of office.
"These protests have a political undertone, they want the referendum to fail. You can see they will go to any lengths... But on Sunday we'll have a democratic electoral day as we should," said Interior Minister Alfredo Rada.
Road blocks, opposition hunger strikes and other protests have been mounting in recent days, forcing Morales to cancel plans to travel to the constitutional capital Sucre this week to give his customary National Day speech.
Eight of Bolivia's nine provincial governors, elected at the same time as Morales in 2005, also face the recall vote on Sunday. One governor took office recently and does not.
In Tarija, police used tear gas to break up dozens of protesters at the airport, shouting slogans against Chavez, who had been scheduled to land there with Fernandez.
The military closed the airport after the protest.
"This suspension (of the summit) was decided due to these acts of violence, provocation and intolerance promoted by bands of fascist, conservative retrograde groups," said Vice President Alvaro Garcia.
Chavez, Latin America's most vocal leftist leader, is a major ally of Morales, pouring aid into Bolivia and pledging investment in its rich natural gas fields.
Chavez and Morales had planned to launch a project to produce natural gas derivatives.
"We don't want Evo, he's a traitor," said Leticia Morales at the airport protest. She said Morales and Chavez "are crazy and we don't want that kind of government in our country."
Morales is popular in the Andean west of Bolivia, but faces rising opposition in Tarija and other eastern provinces where an autonomy movement has blocked his agenda, including a new constitution and land reform.
Morales is the first indigenous leader in mostly Indian Bolivia.
He has nationalized key sectors of the economy, such as energy and telecommunications, and sees the recall vote as ratifying his leftist reforms.
He proposed a recall vote last year to undermine opposition governors, but polls show he and his opponents will probably all be ratified, meaning political strife will continue in Bolivia.
In Huanuni, a perennial hot spot for labour strife, Tuesday's violence erupted when police clashed with groups of striking miners who had blocked the road linking the administrative capital La Paz with the city of Oruro.
Miners at Huanuni, 260 km south of La Paz, launched an indefinite strike last Thursday to back a drive by Bolivia's largest labour federation, the COB, for bigger pensions and a lowering of the retirement age to 55.
The miners supported Morales when he ran for president in 2005, but have frequently caused him headaches since he has been in office.
"This is a massacre and the only one to blame is Evo Morales," Felipe Machaca, a COB leader told radio Erbol.
Republished from TVNZ