A Japanese helicopter belonging to the Ministry of Land, Infrastructure, Transport and Tourism fell into the sea in western Japan on Wednesday afternoon, according to NHK.

Five people were on board when the Japan Coast Guard helicopter crashed off Kagawa Prefecture, after barging in on electrical cables at 3 p.m. local time (0600 GMT), the public broadcaster said.

Rescue workers formed by Japan Coast Guard and local police found part of the helicopter wreckage at sea. The rescue work is still under way and authorities are investigating the incident.

The crash had caused a power blackout in a small island of the western prefecture, affecting some 100 households.