Long-running protests against plans to open a major gold and copper mine controlled by US-based Newmont Mining Corporation forced the closure of a local airport in northern Peru. The airport of Cajamarca, a city of 220,000, was \"temporarily closed to avoid confrontations\" with some 500 protesters who had planned to take it over, airport chief Christian Rocha said. About a hundred passengers headed for Lima were left stranded. Police officers -- some 100 of them -- were deployed around the airport. Several major roads in Cajamarca department were cut off by protesters\' barricades on the fifth consecutive day of the strike by union workers, farmers and environmentalists against Newmont\'s $4.8-billion Conga Project. The open-pit project, located at 3,700 meters (12,140 feet) above the sea level, involves moving the water from four lakes high in the mountains into reservoirs the company would build. Locals say the reservoirs do not adequately replace the lakes, which also provide ground water for agriculture and for raising livestock. The issue is of particular concern in Cajamarca, where a drought has forced water rationing for three months. The conflict is seen as a crucial test for newly elected leftist President Ollanta Humala as he struggles to balance environmental concerns and the rights of local communities with the demands of the mining industry, the engine of Peru\'s economic growth in recent years. Local officials, who support the strike, have repeatedly invited Humala to visit Cajamarca, but only Prime Minister Salomon Lerner has so far agreed to make the trip \"if the conditions are ripe for and local authorities and the regional government allow it.\" Cajamarca, known as the city where the last Inca emperor filled a room with gold to pay ransom for his release from Spanish conquistadores, is located 870 kilometers (550 miles) north-east of Lima. The Spaniards kept the gold and killed the Inca emperor.