Clashes in northern Peru between police and demonstrators opposing a multi-million dollar gold mining project have left at least three people dead.
Hundreds of people attacked government buildings in the town of Celendin, prompting the authorities to declare a state of emergency in the region.
Protesters say the Conga project, financed by US-based company Newmont, will destroy water supplies.
Newmont called a temporary halt to work late last year after similar protests.
Explaining the latest demonstrations, protesters said they had been angered by the town mayor reportedly expressing his support for the open-cast gold mine.
The government has declared a 30-day state of emergency in three provinces in the area, Celendin, Hualgayoc and Cajamarca.
A similar measure was taken in December when President Ollanta Humala declared a state of emergency in Cajamarca after protests against the mine escalated.
Newmont, based in Denver, Colorado, is the majority owner of the Conga project, which was to begin production in 2015 and is an extension of Yanacocha, Latin America's biggest gold mine.
The project, located some 3,700 m (12,140 feet) above sea level, involves moving the water from four lakes high in the mountains into reservoirs the company would build.
The protesters say the reservoirs do not adequately replace the lakes, which also provide groundwater for agriculture and irrigate pasture for livestock.
The Newmont Mining Corporation says its plans have been drawn up in consultation with local communities and meet the highest environmental standards.
It says the Conga mine will generate thousands of jobs. The mine is Peru's biggest foreign investment project.