|Protesters clashed with riot police near Yucumo during their march on Saturday [AFP/Cambio/Calyton Benavides]
Evo Morales, the Bolivian president, has moved to try and defuse a rising ethnic conflict over the construction of a highway through a rainforest reserve by announcing a referendum.
Indigenous people from the Amazon basin lowlands oppose the project, while migrants belonging mostly to the country's two main Andean highland indigenous groups are for it.
"We are going to ask people in [Cochabamba and Beni departments] in a referendum. If they say yes, a study will be done to see where the best route for that road is, the most direct... and with the least environmental impact," Morales, who backs the construction of the road, said on Sunday.
He made the announcement at a protest by farmers from the 16 tribes of the Isiboro Secure National Park in San Antonio, though details of how the vote would be held were not released.
Activists from the Amazon bason left the northern city of Trinidad in mid-August hoping to march on La Paz, the country's capital, in order to protest the plan.
The initial plan had called for the building of a highway through the ancestral homeland of 50,000 natives of three Amazonian groups.
After over a month of hiking from the Amazon rain forest, protesters arrived just outside Yucumo, a small, mainly pro-government town northeast of La Paz, on Saturday after breaking through police barricades.
Police said that they had intervened in Yucumo to prevent a confrontation between the protesters and a group of pro-government demonstrators who had set up a barricade about 300 metres away.
Bolivian media reported that several people had been injured in the clash, but no official toll was available.
Yoriko Yasukawa, the United Nations' deleage in Bolivia, said of the issue: "the most important thing for us is that they stop the violence as soon as possible. And to remind the authorities that it is their responsibility to stop violence and protect the people".
In a separate pledge, Morales said that he would ensure that any illegal settlers in the national park were removed.
Morales, a leftist and member of the indigenous community himself, has been criticised by indigenous activists who say he has not been protecting their lands from "incursion" by members of the ethnic Aymara and Quechua groups.
Morales is the first indigenous person to be elected president of Bolivia, South America's only majority-indigenous country.