Two people were killed and 15 others injured Tuesday in clashes between police and opponents of a controversial mining project in northwestern Peru, the regional health secretary in Cajamarca said.

Reynaldo Nuñez told Canal N television that while the autopsies are pending, the two civilian fatalities apparently died of gunshots and blows to the body.

He said the injured were being treated in the Cajamarca regional hospital and at a clinic in the city of Celendin, the scene of Tuesday's protests.

Nuñez talked to the network hours after the Peruvian Interior Ministry said two police officers suffered gunshot wounds while defending Celendin city hall from an attack by demonstrators.

Speaking in the city of Piura, Cabinet chief Oscar Valdes said the government has the obligation to maintain order and he accused some sectors in Cajamarca of seeking violence.

If necessary, he said, the government will declare a state of siege in Cajamarca.

The head of the Cajamarca regional administration and a leader of the anti-mine movement, Gregorio Santos, expressed solidarity with his "brothers in Celendin."

"This is the government we have: for the miners, everything; for the people, bullets," he said on Twitter.

Around 1,000 opponents of the Conga gold mining project marched through Celendin to city hall, where they clashed with police, Cajamarca administration spokesman Segundo Matta told Canal N.

The protesters targeted Celendin because the city's mayor criticized the movement against Conga.

Peruvian President Ollanta Humala gave the green light for the controversial Conga project in April, but only on condition the mine operators meet conditions aimed at mitigating its environmental impact.

Humala said the Minera Yanacocha consortium - led by Colorado-based Newmont Mining - will have to ensure the availability and quality of water supplies in the area surrounding Conga.

Plans for the $4.8 billion project include draining four alpine lakes to develop subsoil gold deposits and replacing them with artificial reservoirs, a process that is scheduled to get under way soon. EFE