Peru government urges calm before Newmont protest

* Peru wants no violence during gold protest

* Opponents say gold project could affect water supply

By Marco Aquino and Terry Wade

LIMA, Nov 23 (Reuters) - Peru's government urged opponents of Newmont Mining's (NEM.N: Quote) proposed $4.8 billion Conga gold mine project to refrain from violence during a protest on Thursday as President Ollanta Humala scrambles to solve the bitter dispute.

Interior Minister Oscar Valdes said intelligence sources have warned that armed radicals had infiltrated local opposition groups. He said local political leaders in the Andean region of Cajamarca would be held responsible if Thursday's protest turned violent.

Opposition groups say the mine would cause pollution and hurt water supplies.

"I'm warning protest leaders that they can't allow infiltrators to use arms and cause deaths," Valdes said on RPP radio on Wednesday. "The police haven't come here to hurt or kill anybody. We've come to maintain public order."

The Conga impasse has become a crucial test for Humala, a leftist former army officer who campaigned on promises to defuse persistent social conflicts over natural resources that have delayed billions of dollars in investments in the country, one of the world's top minerals exporters. [ID:nN1E7A21FG]

Humala has said he wants the mine, which would be the biggest investment in the history of Peruvian mining, built.