Bolivian officials on Tuesday threatened to prosecute leaders of coca growers who used whips to drive away four unarmed members of a government coca eradication team.
Monday's attack was the second time this year that peasants in the town of La Asunta near this highlands capital have driven away a government-sanctioned eradication mission.
Felipe Caceres, the deputy minister in charge of eradication, said all four men escaped without injury. He told Fides radio the aggressors would be "brought to justice."
No arrests were reported, however.
A local leader from La Asunta, Pascual Mamani, claimed in a radio interview that peasants had administered "community justice" Monday. He vowed continued resistance to eradication in the Yungas region, origin of Bolivia's preferred coca variety.
Coca leaves are the basis for cocaine but also are a sacred plant among Andes natives. A mild stimulant, they have chewed for centuries.
Bolivia is the world's No. 3 coca producer behind Colombia and neighboring Peru with 120 square miles (31,000 hectares) under cultivation, according to U.N. figures.
Bolivia's government eradication force, comprised of soldiers and police, destroyed 38 square miles (10,000 hectares) of coca last year. Less than a third of a square mile (80 hectares) were in the Yungas region.
Nearly all the eradication in Bolivia last year was accomplished in the Chapare region, where President Evo Morales rose to prominence as a coca-growers union leader and still holds considerable sway.
His influence in the Yungas is weaker.
Morales expelled U.S. drug agents in 2008, claiming the Drug Enforcement Administration was seeking to undermine him and incite his political opponents.
His government has been at odds with the United States over how much of its coca crop is needed for traditional uses and thus legal.
The Morales government claims it is 76 square miles (20,000 hectares) while Washington contends Bolivia is obliged to destroy anything over 46 square miles (12,000 hectares).
The U.N. says the Yungas alone has more than 29 square miles (7,400 hectares) of excess coca, nearly all of it in La Asunta.
So far this year, Bolivia has eradicated just three-quarters of a square mile (200 hectares). Authorities say eradication will step up at the end of March when the rainy season ends.