Peruvian military officials say two troops have been killed in an helicopter attack by Shining Path rebels.

They say the soldiers were patrolling the Apurimac and Ene River valley when they came under fire Wednesday.

Authorities say Shining Path rebels have ties to the drug trade in the valley area.

The Maoist Shining Path rebels began their insurgency in 1980, eventually killing tens of thousands of people. Violence declined sharply after the capture and conviction of its founder, Abimael Guzman, in 1992, but the rebels continue to carry out smaller attacks.

Attacks have occurred primarily in remote areas used to produce coca, the raw material used in cocaine.