An officer was killed and 18 others were injured when a police helicopter crashed in the jungle during an anti-drug operation in Mazamari, a district in central Peru, officials said.

The Peruvian National Police helicopter went down Wednesday for unknown reasons while trying to make an emergency landing on the banks of the Tambo River, police aviation chief Martin Mariño told Radio Programas del Peru, or RPP.

Officer Rodolfo Leon, who was flying the helicopter, died in the crash, Mariño said.

The injured officers were taken to the National Police base in Mazamari, which is in Junin region, and will be transported from there to Lima, Mariño told RPP.

The officers were returning to base from Satipo after a mission to intercept a boat carrying drugs and the helicopter experienced mechanical problems, a correspondent for the La Republica newspaper said.

Satipo is in the Valley of the Apurimac and Ene rivers, or VRAE, region, where the remnants of the Shining Path guerrilla group operate.

Ten police officers and soldiers have died in recent weeks in the jungles of southern Peru, where the security forces staged an operation last month to rescue 36 gas company contractors taken hostage by an armed group.

Congress censured two Cabinet ministers in the wake of the security forces members' deaths and Prime Minister Oscar Valdes has tendered his resignation to President Ollanta Humala, who is on a tour of Asia.