By the Associated Press

A civilian was killed and a prominent anti-mining activist arrested in protests on Wednesday against Peru’s biggest gold mining project, further inflaming tensions after the government declared a state of emergency.

Peru’s prime minister, Oscar Valdés, announced the civilian’s death at a news conference in Lima but did not provide further details. It was the fourth protest-related death in two days.

Marco Arana, a former Roman Catholic priest, was arrested hours earlier in Cajamarca, one of three provinces where the state of emergency was declared. A video broadcast by a local TV channel showed riot police scooping him off a bench in the city’s central square and taking him away in a chokehold.

The 49-year-old veteran of anti-mining protests wrote on Twitter that “in the police station they hit me again, punches in the face, kidneys, insults”.

Chief local prosecutor Johnny Diaz told AP he had designated a prosecutor to investigate Arana’s claim. Diaz said Arana was arrested for organising meetings, an activity prohibited during a state of emergency. He said authorities had not issued any arrest warrants or made any mass arrests on Wednesday.

In addition to Cajamarca, the state of emergency was declared in two neighbouring provinces late on Tuesday after three people were killed during a violent protest in the region.

It was the second emergency declared in five weeks to quell the protests. A 30-day emergency period had just ended in Espinar, a highlands province near the former Incan capital of Cuzco. Two people were killed in the area on 29 May while protesting against a copper mine.

The focus of Tuesday’s protest is the $4.8bn (£2.5bn) Conga gold mining project, which was suspended late last year by US-based Newmont Mining Co. Protests were started by local residents who said the mine would hurt their water supplies.

Read more from The Guardian: http://www.guardian.co.uk/world/2012/jul/05/peru-anti-mining-protests-escalate