Around 10 foreigners detained at an immigration facility in Osaka have staged a hunger strike to protest their protracted detention, their supporters said Wednesday.

Almost all of the detainees taking part in the hunger strike, which began Tuesday morning at the Osaka Regional Immigration Bureau, have been held at the facility for over two years, according to the supporters.

(The Osaka Regional Immigration Bureau)

The immigration bureau has refused to comment on the reported hunger strike, saying that "there are no situations that need to be made public."

The detainees are demanding that more goods be available for purchase within the facility and medical services improved, in addition to urging Japan to stop long detention periods and provide specific reasons when provisional release requests are denied.

A Ugandan man in his 40s, who has been detained for more than two years, spoke to a Kyodo News reporter on Wednesday, saying, "We are not criminals but are simply seeking freedom."

"Since Tuesday, we have only been drinking water. It's tough, but we have to hang in," he said during an interview at the facility.

This is not the first case of a hunger strike at a Japanese immigration center.

In April last year, more than 40 detainees at the East Japan Immigration Center in Ushiku, Ibaraki Prefecture, staged a hunger strike days after an Indian man committed suicide at the facility.

The incident was one in a string of deaths at Japanese immigration facilities that have been long criticized for their poor medical services and lengthy detention periods.

Foreigners without legal residency status who receive deportation orders can be detained at 17 immigration facilities across Japan, including in Tokyo, Osaka, Ibaraki and Nagasaki.

The Justice Ministry points to detention as being a way to keep tabs on foreigners who are in Japan without legal status, but supporters, including lawyers, argue it should be limited to short periods before deportation.

The U.N. Committee Against Torture has also criticized Japan's long, and in some cases, indefinite detention periods. There is no legal time limit for detention in the country.