TOKYO: Four Japanese coastguard personnel died in a helicopter crash while rescuers continued to search for a missing crew member, officials said Thursday.

Coastguard helicopter Akizuru crashed Wednesday afternoon after hitting offshore power lines near small islets that are part of Kagawa prefecture in Japan`s southwest.

Four bodies were pulled from the water on Wednesday evening while rescuers spent all night searching for the missing mechanic, Satoshi Odake, 56.

"The search was on all night and we have a fresh search going since the dawn," a coastguard official said.

It was not clear what caused the crash and why the helicopter was flying so low, officials said, adding that the weather was fine at the time of the crash.

The Bell 412EP helicopter had been on a patrol mission.

BDST: 08:32 HRS, August 19, 2010