RAMALLAH, West Bank — Israel has released a Palestinian prisoner who recently ended a 55-day hunger strike. “Khader Adnan, who was in administrative detention, has been released,” said Sivan Weizman, a spokeswoman for the Israel Prison Authority. Adnan, 37, had been hospitalized in critical condition after refusing food since May 4. Israel freed him in the early hours on Sunday, the agreed date for his release. Looking thin and pale, Khader Adnan was transferred in an Israeli ambulance Sunday and handed to the Palestinian medical service. The senior member of Islamic Jihad had been held for more than a year in Israeli administrative detention. Adnan's protests, which included a previous 66-day hunger strike, drew attention to Israel's practice of holding Palestinians without trial or charges. He ended his latest strike two weeks ago in return for a promise to free him. Adnan was originally scheduled to be released Saturday but Israel delayed it until early Sunday, apparently to avoid celebrations by his supporters. He was detained a year ago, shortly after the kidnapping and murder of three young Israelis, which triggered the arrests of hundreds of Palestinians in the occupied West Bank. He had previously gone on hunger strike for 66 days in 2012 to protest against his detention. He was released at the end of the protest, during which he had ingested vitamins and salt. This time, he refused to swallow anything except water. Adnan, a father of six from the West Bank city of Jenin which launched celebrations when he returned home, had begun an extended hunger strike in 2012 that also led to his freedom. Israel has sought to prevent hunger strikes by introducing legislation for prisoners to be force fed, but the measure has hit obstacles, such as condemnation by the national doctors' union, which says it contravenes ethical commitments. The Palestinian government had warned it held Israel responsible for his fate, while the Israeli government in mid-June renewed efforts for legislation that would allow prisoners to be force-fed when their lives are in danger. The Palestinian leadership submitted a report to the International Criminal Court last week that included the treatment of Palestinian prisoners in Israeli jails. — Agencies