Thousands of people in northern Peru have protested against plans for a huge open-cast goldmine in the high Andes.
People in the Cajamarca region say the proposed Conga mine will cause pollution and destroy water supplies.
The US-based mining company Newmont has promised modern reservoirs to replace threatened mountain lakes.
The dispute is a test for President Ollanta Humala, who has promised to continue mining development while protecting affected communities.
Mining is the main engine of Peru’s booming economy, but it is also the cause of numerous social conflicts around the country.
The $4.8bn (£3.1bn) Conga project would be the biggest mining investment in the country’s history.
On foot and on horseback, rural protesters climbed to four high mountain lakes whose waters would be moved to make way for the gold mine.
There were also protests in the regional capital, Cajamarca, 160km (100 miles) away, where schools and businesses closed and buses stopped running.
Previous protests have involved some sabotage of machinery, and the mining camp is closely guarded by police.
Locals say plans to replace the lakes with artificial reservoirs are inadequate.
There are also fears that pollution from the mine could affect agriculture and livestock.
The company behind the project – 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 – which it owns jointly with a Peruvian company – will generate thousands of jobs.
Newmont also runs the nearby Yanacocha mine – Latin America’s biggest gold mine – which has also been the focus of environmental protests.
Peru’s left-wing President, Ollanta Humala, has approved the Conga mine, which would be a major source of government revenue, but this stance has been criticised by some of his supporters.
Mr Humala was elected in June after promising to ensure poor Peruvians saw more benefit from the development of the country’s natural resources.
Since taking office he has also increased taxes on mining companies and given indigenous communities the right to be consulted about development on their land.