The convoy of Bolivia's public works minister was ambushed by protesters, and he briefly disappeared while overseeing the clearing of roadblocks on Saturday.

Mauricio Zamora's vehicle was intercepted in the town of Copata on Saturday afternoon and became separated from the group, local media reported. He was later located and is now safe.

He had been in command of an operation to clear barriers set up by anti-government protesters to slow the flow of goods into the administrative capital, La Paz, and nearby El Alto.

The mission to create so-called "humanitarian corridors" was met by renewed violence from demonstrators, with some convoys reportedly attacked with stones and dynamite.

Marches, protests and roadblocks by trade unions and supporters of left-wing former President Evo Morales have intensified this week, with clashes with security forces in La Paz.

The demonstrators are hoping to put pressure on Bolivia's centre-right President Rodrigo Paz to resign just six months after taking office, over his government's austerity measures, with his alignment with the US another divisive issue.

Bolivia's police and military were dispatched from major cities in the early hours of Saturday morning to clear the roadblocks, deploying bulldozers to clear rocks and concrete pillars, aiming to ease the flow of food and medicine into the capital.

But in several places, clashes with protesters broke out, and roadblocks were re-established.

Zamora's convoy had been travelling through Copata, south of La Paz, when residents began pelting it with stones and dynamite, local media reported.

His vehicle became separated from the others as they retreated, but was able to take a dirt road, according to Agencia Noticias Fides. Here, though, it suffered a second ambush before eventually reuniting with the convoy.

Elsewhere, protesters looted and burnt down a customs post in Achicha Arriba, on the highway into El Alto, after police used tear gas to attempt to disperse protesters there.

Near Caracollo, north of Oruro, a convoy was attacked with explosives. Demonstrators burnt a military truck and looted a police station, while a minibus was burnt on the La Paz-Oruro highway, according to the daily newspaper La Razon.

The government denied reports - repeated by Morales - that a person had been killed in the town of Vilaque, on the same highway. Several outlets reported that journalists covering the operation were also coming under attack.

Paz was elected on a promise to end Bolivia's worst economic crisis in decades.

But his decision to scrap long-standing fuel subsidies amid shortages and inflation has raised living costs and enraged a sizeable portion of the population.

Morales - who is currently being protected by supporters while facing criminal allegations of having a relationship with a minor while president - has supported the protests, having long harboured opposition to US involvement in Latin America. Paz's government accuses him of instigating the unrest.

The centre-right leader said he was exploring every avenue of dialogue with the demonstrators, but told Argentine news outlet Todo Noticias on Saturday: "Everything has a limit."