Khader Adnan, a senior member of the Palestinian militant group Islamic Jihad, who was accused by Israel of "involvement in terrorist activities," died in Israeli custody on Tuesday after an 87-day hunger strike, Israel's prison service announced.

Israel said Adnan "refused to undergo medical tests and receive medical treatment" and "was found unconscious in his cell" early on Tuesday morning. Israeli prison authorities said Adnan was brought to a hospital but attempts to revive him failed.

Adnan's lawyer accused Israel of medical negligence. "After 36 days of Adnan's arrest, we demanded he be moved into a civil hospital where he can be properly followed up. Unfortunately, such a demand was met by intransigence and rejection by the Israeli prison authorities," Jamil al-Khatib told Reuters news agency by phone.

Adnan, 45, is the first Palestinian to die as a direct result of a hunger strike, according to the Wa'ed Prisoners' and Ex-Prisoners' Association, an advocacy group for jailed Palestinians, based in Gaza.

Who was Khader Adnan?

Adnan, originally from Jenin, was a well-known figure in the Israeli-occupied West Bank.  The group he was affiliated with, Palestinian Islamic Jihad, or PIJ, is classified as a terrorist organization by the United States and other countries in the West. 

According to the Wa'ed Prisoners' Association, Adnan had been detained by Israel 12 times, spending around eight years in prison over around the past two decades, mostly under administrative detention. Under so-called administrative detention, suspects are held indefinitely without charge or trial. To protest this, Adnan went on at least five hunger strikes during his various times in custody since 2004. That included a 56-day strike in 2015 and a 66-day strike in 2012. 

Israel says the controversial detention tactic helps authorities thwart attacks and hold dangerous militants without divulging incriminating material for security reasons.

Israel is currently holding over 1,000 Palestinian detainees without charge or trial, the highest number since 2003, according to the Israeli human rights group HaMoked. Such prisoners commonly go on hunger strike but are usually released to medical care. 

IDF reports more than 20 projectiles following death

Adnan's death was followed by exchanges of fire between Israel and Palestinian militant groups during a period of already high tension. 

The PIJ had described his death as a "crime" on the part of Israel and threatened reprisals on Tuesday. 

According to Israel's military, the IDF, three rockets were fired by militants from Gaza soon after Adnan's death. The IDF said that its retaliatory tank fire was met with a further 22 projectiles launched from Gaza. It said four of the projectiles were intercepted and the rest fell on open ground. 

dh/msh (AP, Reuters, AFP)