(BSS/AFP) - Peruvian prosecutors on Monday launched a preliminary probe into eight soldiers accused over the killing of five people during a drug raid in a coca-growing region.

The incident took place on Saturday on a road in the south-central Andean region of Huancavelica.

Eight soldiers on patrol signalled to a van carrying eight people to pull over.

When the driver failed to stop, the troops opened fire on the vehicle, killing five passengers and injuring the other three, local prosecutors said.

Local media said the victims included young sportspeople and workers who had no involvement in the drug trade.

The eight soldiers, who included an army captain, were arrested.

The military in a statement claimed that the troops acted "in self-defense" after "being attacked by individuals suspected of links to narcotrafficking networks."

Huancavelica is situated in a vast river valley which has the biggest coca-growing acreage in all of Peru.

Coca is the main ingredient in cocaine, of which the South American country is the world`s second-biggest producer after Colombia.