One person was killed and seven others injured when a military helicopter crashed in the jungles of Darien during a counter-narcotics operation, Panamanian authorities said.

Among the injured was Commissioner Belsio Gonzalez, director of the National Aero-Naval Service, or SENAN, a source in that service told Efe.

A ninth person who was aboard the chopper escaped unhurt, the source said.

The accident took place at around 3:00 a.m. in the Mamsuggun area of Panama's Caribbean coast, near the border with Colombia, SENAN said in a statement.

"The helicopter crashed during the development of a drug-interdiction operation," the statement said, offering no information on the cause of the accident.

Six SENAN personnel were aboard the aircraft, along with a pilot, co-pilot and flight engineer.

The injured were taken to hospitals in Panama City, public television said. EFE