By Terry Wade and Marco Aquino
LIMA (Reuters) - Peruvian lawmakers on Thursday harshly criticized President Ollanta Humala's crackdown on protests against Newmont's $5 billion Conga mine, as deadly violence prompted calls for him to shuffle his Cabinet.
A fifth protester died on Thursday after two days of clashes with police as left-wing leader Marco Arana, a soft-spoken former Roman Catholic priest who has rallied demonstrators to stop construction of the biggest mine in Peruvian history, was released from police custody a day after a video aired on local TV showed him being detained and beaten by police.
He was ostensibly detained for violating emergency rules that suspended the right to protest in the northern region of Cajamarca.
"The government is mistaken if it thinks that with bullets, torture and punches it will control the just demands of Cajamarca," Arana said at a news conference. "The president shouldn't just defend investment. He should defend the fundamental rights of Peruvians."
Arana, who is widely thought to have ambitions to seek the presidency in the 2016 election, and his allies on the left say Humala has drifted too far to the right since taking office last year.
They say the president and has put the interests of global miners ahead of those of poor peasants to ensure that $50 billion in planned mining projects get built in one of Latin America's fastest-growing economies.
Opponents of the Newmont mine say it would cause pollution, hurt water supplies and fail to generate enough local economic benefits. Humala has backed the project as a generator of thousands of jobs and enormous tax revenues.
Humala, a former military officer, has not spoken about the violence this week - even as his ministers suspended freedom of assembly to quell the rallies and opposition lawmakers urged police to show more restraint.
Five lawmakers who left Humala's Gana Peru in the last few weeks over ideological differences urged Prime Minister Oscar Valdes and Interior Minister Wilver Calle, both former military officers, to quit.
"We demand they quit immediately ... for their manifest political and administrative incapacity to resolve the social conflict that exists in Cajamarca," the lawmakers wrote in a public letter.
The clashes this week, the first in eight months of protests against the mine, marked the biggest political setback for Humala since the first round of protests against the Newmont mine prompted him to shuffle his Cabinet in December - after only five months in office.
Peruvian leaders normally shuffle their Cabinets around July 28, Peru's Independence Day, and expectations are growing that Valdes will be pushed out.
Right-wing lawmaker Keiko Fujimori, who narrowly lost to Humala in last year's election but whose party has sometimes lent him support in Congress, urged her former rival to show more leadership.
"President Humala: grab the bull by its horns. Leave the comfortable presidential palace, stop taking foreign trips and go fight the enemies of Peru," she said while criticizing "radicals" for trying to stop progress.
Humala took office urging mediation to solve hundreds of disputes nationwide over natural resources, but he has lost patience with protesters and has suspended civil liberties to curb demonstrations at least three times.
15 DEAD IN PROTESTS THIS YEAR
Members of Humala's party have blamed Arana and another strident opponent of the mine - Gregorio Santos, the president of the Cajamarca region - for inciting violence at a rally of 2,000 people on Tuesday where protesters threw rocks and vandalized public buildings. The rallies spilled over into Wednesday.
Official data shows at least 15 people have died during Humala's term in protests over natural resources, compared with 174 who were killed in similar circumstances from 2006 to 2011 when Alan Garcia was president.
Amnesty International urged all sides to show more restraint to avert further violence. Health officials said this week's five victims were killed by rounds of live ammunition - contradicting statements by the police that only rubber bullets and tear gas were used to disperse crowds.
U.S.-based Newmont's project in Cajamarca, known as Conga, is partly owned by local miner Buenaventura and would produce between 580,000 and 680,000 ounces of gold annually. Conga would essentially replace the nearby Yanacocha mine run by Newmont and Buenaventura that is nearing the end of its life.
Protesters have expressed outrage that Humala gave the miner permission a week ago to proceed with construction of the project after Newmont agreed to comply with a more stringent environmental mitigation plan recommended by outside experts.
Newmont has agreed to build larger reservoirs that would replace two or more in a string of alpine lakes and guarantee year-round water supplies in towns that suffer during the dry season. It started work on those reservoirs over the weekend after nearly all construction work on the mine had been stopped since November because of protests.
The company's local office said on Tuesday the violence was unfortunate, but that the company was "reaffirming its commitment to Cajamarca."
Peru, which has vast mineral resources, is the world's second-largest producer of copper and sixth of gold, but many mining communities suffer from widespread poverty and complain a decade-long economic boom has passed them by.
(Editing by Vicki Allen and Mohammad Zargham)