Khader Adnan, a Palestinian prisoner who went on a 66-day hunger strike over his detention without charge by Israel, has been released following a deal reached in February.

Adnan has since arrived at his home in the West Bank village of Arabah on Tuesday. He had refused food from December 18 until February 21 in protest over what he said was a violent and humiliating arrest and interrogation.

The detention of Adnan, a 33-year-old baker who was arrested "for activities that threaten regional security" due to his alleged leadership role in Islamic Jihad, an armed Palestinian group, triggered a series of protests calling for his release across Palestinian territories.

Earlier this year, an Israeli military court ordered that Adnan be placed for four months in administrative detention. Under Israeli law, such prisoners can be held indefinitely without trial or charge.

Human rights groups criticized the conditions in which he was being held at Ziv hospital in the northern Israeli town of Safed, where he was shackled to his bed by chains on both legs and one arm.

Mass Hunger Strike

Prior to his release on Tuesday, at least 1,200 Palestinian inmates of Israeli jails began an open-ended hunger strike, as rallies across the occupied territories marked "Prisoners’ Day".

As thousands gathered in towns and cities in both the West Bank and the Gaza Strip, three-quarters of the 4,700 Palestinians held by Israel began refusing food, the Israel Prisons Service (IPS) said.

"In the framework of (Palestinian) Prisoners’ Day, around 2,300 security prisoners said they were refusing their daily meals, and around 1,200 prisoners said they were starting a hunger strike," IPS spokeswoman Sivan Weizman said on Tuesday.

Another eight women inmates had also said they were refusing food as a show of solidarity with the Palestinian security prisoners, Weizman said.

"We have coped with hunger strikes in the past and we are prepared to do so again now," she added.

Speaking to crowds gathered in the northern West Bank city of Nablus, Qadura Fares, head of the Palestinian Prisoners Club, gave a higher figure for the hunger strike, saying "1,500 prisoners from all the factions" had joined it already and more were expected to later in the month.

"We are united and undivided when it comes to prisoners, and we will stand by them until they get their demands," he said.

The Palestinian Prisoner Affairs Ministry says there are about 4,700 Palestinians being held in Israeli prisons, including 319 being held without charge in so-called "administrative detention".

(Agencies via Al Jazeera)