A civilian helicopter crashed into a reservoir in a northern city Tuesday, with a rescue operation under way for one person suspected to be on board, officials said.

The aircraft crashed in the reservoir in Pocheon, 52 kilometers northeast of Seoul, at 11:08 a.m., according to the officials.

The helicopter is currently underwater in the reservoir, which is estimated to be 10-13 meters deep.

Police and rescue authorities have mobilized 67 personnel, including two divers, for the rescue effort.

The AS-350 helicopter is known to have crashed while conducting a forest fire prevention exercise.

Source: Yonhap News Agency