The Immigration Bureau said Friday that a number of detainees at the Tokyo Regional Immigration Bureau are on hunger strike.

A support group working with the detainees said their main demand was that Japan revise its policy, especially in regard to prolonged or consecutive detentions.

According to the bureau, which is overseen by the Justice Ministry, 560 detainees are being held at the Tokyo facility in Minato Ward and at least 20 were on hunger strike as of Friday noon.