The local authorities said the graves were on the site of a former military base, but would not speculate as to whether the army or the guerrillas - such as the far-left Shining Path (Sendero Luminoso) - were responsible for the deaths.

The area has now been cordoned off and officials have launched a full inquiry. Forensic scientists are on their way to the region to investigate.

Army base

According to Silvio Campana, the ombudsman for the southern city of Cusco, the village was taken over by the armed forces and used as a base during their fight against leftist rebels during the 80s and 90s.

Residents, who returned to the village after years away, unearthed the graves.

I saw a couple of skulls, one of which was split open, and a load of bones in a grave where residents said 20 bodies were brought, but they have indicated there are three more graves with a similar number of bodies

Local official Silvio Campana

Mr Campana refused to say whether the military was to blame, saying that guerrillas from the Shining Path and the smaller Tupac Amaru Revolutionary Movement (MRTA) movements were also active in the zone.

"I saw a couple of skulls, one of which was split open, and a load of bones in a grave where residents said 20 bodies were brought, but they have indicated there are three more graves with a similar number of bodies," Mr Campana said.

Bloody conflict

Some 30,000 Peruvians died during the guerrilla warfare which lasted from 1987 to 1991.

Correspondents say the discovery could influence next month's second-round vote for the Peruvian presidency, as the bodies may be those of people who disappeared when one of the candidates, Alan Garcia, was president.

Shining Path, considered one of the most bloody rebel movements in Latin America, killed and carried out car bombings in its bid to replace the government with communist rule.

The MRTA is best known for a 126-day hostage siege in the Japanese ambassador's residence in Lima in 1996-97.