Thousands of Palestinian mourners have gathered in the town on Sair in the occupied West Bank for the funeral of Arafat Jaradat, who died in an Israeli jail under disputed circumstances.
Palestinian officials say preliminary autopsy results show Jaradat's death on Saturday was caused from torture by his Israeli interrogators. Israeli officials say there is no conclusive cause of death and that more tests are needed.
Monday’s funeral comes at a time of rising tensions after weeks of protests by Palestinians outraged over Israel’s treatment of thousands of Palestinians prisoners.
The demonstrations have stoked Israeli fears of a third Palestinian uprising.
Palestinian Authority (PA) police kept order as Jaradat's funeral got under way, while Israeli forces remained outside the village.
Al Jazeera's Nicole Johnston, reporting from the funeral, said people in Sair "never believed the official Israeli version of events … that he had died of a heart attack".
"There is a great deal of concern across Israel and the Palestinian territories that this death, and the last few weeks of protest about the issue of Palestinian political prisoners inside Israeli jails, could lead to further uprisings, demonstrations and clashes between Palestinian protesters and the Israeli army," she said.
"At this point it’s difficult to know if the situation will calm down in a few days or if these protests will intensify."
Fighters from the al-Aqsa Martyrs Brigades, the armed wing of PA President Mahmoud Abbas's Fatah movement, vowed on Monday to avenge the death of Jaradat.
"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, while masked members of the group fired assault rifles into the air.
Palestinians have been staging regular protests demanding the release of prisoners, particularly several who are on hunger strike, but 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.
Israel on Monday demanded that the PA rein in unrest. "Israel expects the Palestinian Authority to act responsibly to prevent incitement and violence which will only exacerbate the situation," said Mark Regev, a spokesman for prime minister Binyamin Netanyahu.
Issa Qaraqaa, the Palestinian minister of prisoner affairs, accused Israel on Sunday of torturing Jaradat to death, citing the preliminary findings of an Israeli-Palestinian autopsy.
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".