A United Nations human rights expert called for negotiations between indigenous people and Bolivian authorities today after protests against the construction of a highway in the Amazon turned violent last Sunday.

Around 1,500 protesters clashed with police, resulting in a high number of detainees and injured individuals as well as possible casualties, according to a press released by the UN Office of the High Commissioner for Human Rights (OHCHR).

UN Special Rapporteur on the Rights of Indigenous Peoples James Anaya called for the Bolivian Government to “take all the necessary measures to guarantee the security of the people that are participating in the protest, in addition to preventing, investigating and sanctioning any act that affects the life and integrity of these measures.”

He also urged “the immediate start of a consulting process in good faith with indigenous people, with the end of finding a peaceful solution to this situation.”

The protest is currently focused on the town of Yucumo, where about 1,000 people have blocked access to food, water, and medicine to the area.

The proposed highway would cross the Isiboro Secure National Park and Indigenous Territory (TIPNIS), which is home to 15,000 indigenous people who live largely off hunting, fishing and subsistence farming. The highway’s construction would affect not only its indigenous population, but also the lives of the 3,000 species that inhabit the reserve.

In his annual report for UN Human Rights Council, Mr. Anaya remarked that development projects, along with the exploitation of natural resources, have become “one of the most significant sources of human rights abuse against indigenous people in the world.”