More than 20 foreigners at an immigration facility in Nagoya have launched a hunger strike, protesting long detention periods and their conditions, their supporters said, as more than 20 foreign detainees continued a separate hunger strike at an immigration facility in Tokyo.

At the Nagoya facility, male detainees from countries including Iran, Turkey and Vietnam have been refusing to eat since Monday, their supporters said on Tuesday.

The detainees in Nagoya, including a man who has been at the facility for about 11 months, are seeking early provisional release, better treatment and the improvement of medical services.

A 31-year-old Iranian man, who has been detained for about six months, told a Kyodo News reporter at the facility that he will continue the hunger strike until death if necessary as nothing has changed despite repeated pleas.

An official of the Nagoya regional immigration bureau said it was "confirming" the situation.

About 150 people are currently being detained at the facility, according to the regional immigration bureau, including some whose criminal convictions have already been finalized.

At the Tokyo immigration facility, Chinese, Myanmar and other foreign nationals have been refusing meals since last Tuesday, demanding an improvement in their detention conditions.

The hunger strikes follow the death in March of a Vietnamese man in his 40s who was found unconscious in his room at an immigration facility in Ibaraki Prefecture. Reuters reported that the man died of a stroke and had been left lying in the room for hours before he was taken to a hospital.