About 60 detainees at the East Japan Immigration Control Center in Ushiku, Ibaraki Prefecture, have been on hunger strike since Monday to seek better treatment, a Tokyo-based volunteer group member said Wednesday.

Meanwhile, center spokesman Hiroki Shimizu confirmed to The Japan Times that about 30 detainees, rather than 60, have refused to eat since Monday.

"The living conditions at immigration detention centers are really bad. We have been asking for improvement, but nothing has happened," Mitsuru Miyasako of Bond, a group supporting foreign workers in Japan, told The Japan Times.