Massive show of support for jailed Palestinian Khader Adnan, who is “in immediate danger of death”, medical NGO says.

The father and daughter of Khader Adnan took part in a rally in Adnan’s West Bank village of Arabeh [Reuters]

Several thousand Palestinians have rallied in Gaza and the West Bank in support of jailed Islamic Jihad leader Khader Adnan, who is on the 63rd day of a hunger strike to protest against his detention by Israel.

“We are all Khader Adnan,” chanted crowds gathered in the Gaza Strip on Friday, with activists from the main political factions joining forces in a rare display of Palestinian unity.

Adnan, 33, has been refusing to eat since mid-December following his arrest in the occupied West Bank.

He is being held under so-called administrative detention, which means Israel can detain him indefinitely without trial or charge.

The demonstrations came as Adnan’s lawyers appealed to Israel’s Supreme Court, demanding his release.

“We are hoping … the Supreme Court hears this case urgently,” said Mahmoud Hassan, one of Adnan’s lawyers. “He could die before the court hearing,” for which a date has not been set yet, he said.

In previous cases, the high court at times reduced the sentence of administrative detainees on appeal, but that it rarely ordered them freed outright, Hassan said.

The Islamic Jihad group, which is pursuing an armed conflict against Israel over its occupation, has said it will escalate violence if Adnan dies, following reports that his health was deteriorating.

“We will pursue our Jihad and resistance. We will sail in the sea of blood and martyrdom until we land on the shore of pride and dignity,” Nafez Azzam, one of the group’s top leaders, said during a Friday sermon at al-Omari mosque, the oldest in Gaza.

The Physicians for Human Rights (PHR) group in Israel, which has been monitoring Adnan’s condition in an Israeli hospital, said on Friday that he was “in immediate danger of death”, adding that he had suffered “significant muscular atrophy”.

The Israeli army said in a statement that Adnan was arrested “for activities that threaten regional security”. It has not given further details.

Adnan owns a bakery and a fruit and vegetable shop in his West Bank village, Arabeh. He has served as a spokesman for the Islamic Jihad, which describes him as a local leader.

At least 5,000 people took to the streets of Gaza, waving a mix of black Jihad flags, the green flags of Hamas and the yellow flags of the Fatah movement of Mahmoud Abbas. the Palestinian Authority president .

Witnesses said hundreds had also demonstrated in the northern West Bank city of Jenin.

Palestinian officials said many other prisoners in Israeli jails had started hunger strikes to support Adnan, including Hassan Salama, a senior armed commander of Hamas who is serving life terms for masterminding suicide bombings against Israelis.

Palestinian prisoners have regularly staged hunger strikes in the past to try to gain better conditions or to denounce the Israeli occupation of Palestinian Territories.

However, such protests usually end quickly and officials said no-one had persisted for as long as Adnan, who is married with two children and whose wife is expecting a third infant.

Azzam accused Arab states and Western powers of ignoring Adnan’s protest. “Shame on the nations of hundreds of millions [of Muslims] for the fact that Khader Adnan is still in prison,” he said in his Friday sermon.

Hamas, which governs Gaza, said it was pushing the Arab League and Egypt to press for the release of Adnan.

“The Palestinian people, with all its components and its factions, will never abandon the hero prisoners, especially those who lead this hunger strike battle,” said Ismail Haniyeh, Hamas’ top authority in the Mediterranean territory.

The PHR rights group said Adnan could die even if he broke his fast.

“There is a risk to his health even if he starts eating now because his system has got used to not having any food at all,” a spokesman said.