Palestinian militants of the Al-Aqsa Martyrs Brigades stand guard on the roof of a building in the West Bank village of Saair on February 25, 2013 during the funeral of Arafat Jaradat, an inmate who died in an Israeli prison.

Militants of the Al-Aqsa Martyrs Brigades, the armed wing of Palestinian president Mahmud Abbas's Fatah movement, vowed on Monday to avenge the death of a prisoner they say was tortured in an Israeli jail.

“This horrific crime will not go unpunished and we promise the Zionist occupation that we will respond to this crime,” said a statement distributed to crowds at the funeral of Arafat Jaradat, while masked members of the militant group fired assault rifles into the air, AFP journalists at the scene reported.

The militants were among thousands of people, many waving Fatah banners or Palestinian flags, who flocked to Sair, Jaradat's home village near the city of Hebron in the southern West Bank, for his burial there.

“Al-Aqsa brigades, the armed wing of the Fatah national liberation movement, mourns with all pride its hero, the martyr of freedom, the prisoner Arafat Jaradat,” the statement said, in reference to Jaradat's membership of the group.

Israeli forces stayed just outside the village.

Palestinians have been staging regular protests demanding the release of prisoners, particularly several who are hunger strike, but the tensions have soared since Jaradat's death.

On Sunday a Palestinian man was seriously wounded after he was hit by live fire near Ramallah, and two others were injured in the same protest near Ofer prison, medics said.

AFP journalists saw Palestinians clash with Israeli security forces in Hebron, Ramallah, Nablus and Jenin.

The Palestinian minister of prisoner affairs, Issa Qaraqaa, on Sunday accused Israel of torturing Jaradat to death, citing the preliminary findings of an Israeli-Palestinian autopsy.

Israeli prison authorities had initially said he appeared to have died of a heart attack.

Qaraqaa said the autopsy carried out at Israel's national forensic institute in the presence of a Palestinian doctor, indicated bruises on Jaradat's torso and damage to muscles, as well as broken ribs.

Israel released a similar account of the post mortem but stressed that there were “fractures in the ribs” which “could be testimony to resuscitation efforts.”

“These preliminary findings are not sufficient to determine the cause of death,” a statement from Israel's health ministry read, noting that microscopic and toxicological findings were still pending.

A spokeswoman for the Israeli Prisons Service said that most of the 4 500 prisoners who on Sunday staged a one-day hunger strike to protest Jaradat's death had resumed eating, except for about 1 000 at Megiddo prison, where Jaradat died, who are staging a partial protest.

“They refused breakfast and will refuse tomorrow. They're only refusing their breakfast, they're taking all the other meals,” Sivan Weizman told AFP.

She said that three veteran hunger-strikers were still in Israeli hospitals where they were taken at the end of last week for checkups but said that she could not divulge details of their medical condition.

“They are being treated in hospital,” she said.

Rights organisations and Palestinian prisoner support groups say the three, and a fourth prisoner under observation in the medical wing of a prison in central Israel, have been on hunger strike for several months.

The Ramallah-based Prisoners' Club announced Saturday that another seven prisoners had joined them. - AFP