The death of a Nigerian man following a hunger strike in a protest over his long incarceration at an immigration center prompted dozens of detainees at the facility in Nagasaki Prefecture and elsewhere to start fasting, raising questions about authorities’ handling of the situation.

A petition signed by 95 detainees at the Omura Immigration Center, where the Nigerian man was held for an unspecified period, requested an investigation into the case and measures to prevent a recurrence.

Detainees at immigration facilities in Ibaraki Prefecture and Tokyo also began going on hunger strikes.

The Nigerian detainee was in his 40s when he died in June.

The man was found unconscious in his cell on June 24, and later pronounced dead.

Officials at the center have not published his name and age, nor divulged how long he had been held there.

The Omura Center reportedly said “the cause of death has been identified, but cannot be released.”

According to supporters familiar with the case, the man was transferred to the Omura center after first being taken into custody at the Osaka Regional Immigration Bureau about three years and seven months previously.

He began the hunger strike in spring to protest his prolonged incarceration and request provisional release. He was alone in his cell in the days leading up to his death.

Many detainees incarcerated for long periods either have families in Japan or have applied for refugee status.

Even though the detainees face deportation, Japanese immigration authorities are loathe to send detainees back to their home countries if they have no visible means of support. As a result, detainees often endure long stays in an immigration center.

There were 111 detainees at the Omura Immigration Center at the end of July.

Of these, 95 signed the petition calling on authorities to get to the bottom of the Nigerian man’s case so that "his life is not wasted.” They also questioned the rationale of such long detentions. One detainee there has been held for six years and eight months.

The detainees who signed the petition represented about 20 countries, among them, Iran, Sri Lanka, Pakistan, Vietnam, Nepal, China, Turkey and Brazil.

It was handed to the center’s chief on July 19.

“A precious life was lost after a detainee became anxious with no clues about his future following long-term detention,” said the statement written in Japanese. “How many more detainees have to die before the Immigration Services Agency of the Justice Ministry alters its ways?”

Submitting the petition was characterized as a bold gesture as it could undermine the detainees' chances for provisional release. Immigration authorities decide on detention periods at their discretion.

Kunihiro Kawada, a supporter of foreign detainees, said those held at the Omura center learned of the man's death a day later through a TV news report.

They demanded an explanation from officials at the detention center, but were not satisfied with the result and refused to eat their evening meal in a symbolic gesture.

A Nepalese man who knew the Nigerian told The Asahi Shimbun that another detainee who saw him before his death described him as “so thin, like a ballpoint pen.”

Some of the detainees began a hunger strike in protest. As of Aug. 4, 11 were continuing with the hunger strike, according to supporters of foreign detainees.

Detainees at other immigration facilities also joined the protest.

On July 21, an Iranian man at the Higashi-Nihon Immigration Center in Ushiku, Ibaraki Prefecture, told The Asahi Shimbun over the phone from the facility that he was in his ninth day of a hunger strike and that 65 were refusing to eat.

“This is our fight to get across the message that long-term detention is wrong,” said the Iranian, who has been held there for about three and a half years. “We have committed no crime. I do not want to die, but our message will not be heard unless we endanger our health.”

At the Tokyo Regional Immigration Bureau in the capital’s Minato Ward, several female detainees protested their extended detention in late July and refused to ingest foods other than vegetable juice and milk.

One of the woman, speaking in a feeble voice during an interview with The Asahi Shimbun, demanded to know why she has been detained for so long.

Hiroshi Yunohara, a 51-year-old pastor who meets with detainees and performs religious services at the Omura Immigration Center, said detainees were infuriated by the Nigerian man's death.

He said it should not come as a surprise if others also fast until death to make their protest heard.

“The immigration authorities should sincerely respond to their request,” he said.

Justice Minister Takashi Yamashita said an inquiry is under way when he was asked at a news conference on July 2, and again on July 29, about the Nigerian man’s death.

“The Immigration Services Agency has formed an investigative team and is looking into the case,” he said. “The ministry is taking a flexible approach toward foreign detainees who have been held for a prolonged period by flexibly granting provisional release if it is deemed extremely difficult to deport them due to health reasons.”

There are 17 immigration centers in Japan for foreign nationals who have overstayed their visas.

As of July 19, the number of detainees came to 1,282.

There were 681 individuals who had been detained for more than six months as of the end of 2018. The figure compared with 290 as of the end of 2014.

In contrast, fewer are granted provisional release.

At the end of last year, 2,501 detainees were discharged on provisional release. The comparable figure for the end of 2014 was 3,404.