REUTERS - A man protesting Southern Copper Corp's $1.4 billion dollar Tia Maria project in Peruwas killed in clashes with police on Tuesday, the second death in two weeks as government talks with opponents remain thwarted.

Interior Minister Jose Luis Perez said authorities were investigating how the protester was killed and two others wounded in Peru's southern region of Arequipa.

"In this conflict, which has been going on for a month and a half now, 140 police officers have been injured, some of them seriously. Unfortunately, late last night we were informed there was a death and the causes of this person's death are being investigated right now and I am told there are two others injured. We are not discarding any possibilities, but for the umpteenth time, just like all the ministers who have gone to Arequipa and to Islay, I want to say that from the start, the government has sought dialogue and peace," Perez said.

Perez, who said he had ordered police not to use lethal weapons, replaced local law enforcement chiefs after another protester died from a bullet wound April 22.

Construction on Tia Maria was poised to start when the protests broke out more than 40 days ago.

Southern Copper said last week that the protests might delay the project's 2017 start date and that progress hinged on talks between opponents and the government of President Ollanta Humala, who supports Tia Maria.