A guerrilla attack on Peruvian soldiers on the eve of the country's presidential elections killed seven people, authorities said Sunday, raising the previous day's toll.

The head of the state prosecution service, Pablo Sanchez, said in a televised address that seven people were killed and five wounded in Saturday's attack in the jungles of central Peru.

The military earlier gave a toll of four killed -- three soldiers and a civilian. They said guerrillas attacked a military convoy that was transporting electoral material and forces to guard voting stations in the central Junin region.

Authorities blamed remnants of the Shining Path communist guerrilla group, which was largely crushed in the 1990s but still has members hiding in the jungle.

The army said attackers first struck at Hatun Asha, located in a jungle zone considered a stronghold of the guerrillas and a major coca-producing area.

In a second attack, they targeted a military ship on the Apurimac River in the south, wounding two soldiers, authorities said.

President Ollanta Humala condemned the "demented" violence.

"Terrorism and those who collude with it have no place in our society or in our family," he said on Saturday.

Some 23 million Peruvians were called to vote on Sunday for a new president and members of congress.

Mariano Cucho, head of the National Office of Electoral Processes, insisted that "this attack will not tarnish the elections."

Leading the polls is conservative candidate Keiko Fujimori, whose father Alberto Fujimori waged a fierce conflict against the Shining Path when he was president from 1990 to 2000.

Around 69,000 people were killed between 1980 and 2000 in the conflict with the Shining Path, according to the country's Truth and Reconciliation commission.

"Peru has lived through these violent periods and we are working to bring peace to the country," Humala told a news conference.

"All these demented acts do is unite the Peruvian people more."

Authorities say remaining members of the guerrilla group have joined forces with drug gangs and remain active in remote mountains and jungles.

Peru is one of the biggest coca leaf and cocaine producers in the world, according to the United Nations and US authorities.