About 50 detainees being held at the Osaka Regional Immigration Bureau went on a hunger strike Wednesday to protest what they call "inhumane" treatment by Immigration Bureau officials, a group supporting them said.

The detainees believe officials at the facility are using intentional mistreatment to make them want to return to their home countries, said Nobukazu Nagai of the detainee support group Provisional Release Association in Japan (PRAJ).

Those being held are mainly individuals who have been ordered to leave and are appealing their deportation ruling or asylum seekers whose applications are under consideration.