Dozens of Palestinians were injured Sunday including two shot with live bullets at demonstrations across the West Bank to protest the death of a Palestinian in Israeli custody.

At least 26 protesters sustained wounds from rubber and live bullets during clashes near Ofer prison, west of Ramallah, medics said.

The 13-year-old son of a Preventive Security officer was taken to Ramallah government hospital after he was shot in the chest with a live bullet at the protest. A 19-year-old was shot with rubber-coated bullets all over his body, a Ma'an reporter said.

An Israeli military spokeswoman said protesters hurled rocks at soldiers who responded with riot dispersal means. She said the army was looking into whether live fire was used at the protest.

The army spokeswoman said live fire were used at al-Arrub refugee camp and that one protester was shot with a live bullet.

Across Gaza and the West Bank, hundreds protested the death of Arafat Jaradat, a 30-year-old who died on Saturday in Israel's Megiddo prison.

Palestinian Authority Minister of Detainee Affairs Issa Qaraqe said Jaradat, from Hebron, died after being tortured during interrogation by Israeli forces and demanded an international investigation into interrogation techniques used by Israel.

Several mass protests were held across Hebron on Sunday, in al-Arrub refugee camp, Beit Ummar and Halhul, and in Bethlehem, Qalqiliya and Tulkarem.

In Beit Einun, in the Hebron district, a young man was it in the head with a rubber bullet and hospitalized. An Israeli military spokeswoman said five protesters were hit by rubber bullets at the protest.

In the northern West Bank, Israeli forces fired tear gas at protesters demonstrating at al-Jalameh checkpoint. Odai Zakarneh, 16, was hit by an Israeli army jeep and was taken to Jenin Hospital with a broken foot.

Israel on Sunday demanded the Palestinian Authority stem the protests ahead of US President Barack Obama's visit to the region next month.

A senior aide to President Mahmoud Abbas gave no indication the PA, which exercises limited self-rule in the occupied West Bank, would issue any call for calm, and blamed Israel for the spike in unrest.

Over 4,000 prisoners held a one-day fast on Sunday after the detainee's death, which Israel said was caused by a heart attack, an explanation challenged by Palestinian officials.

"Israel has conveyed to the Palestinian Authority an unequivocal demand to calm the territory," an Israeli government official said, adding the message was delivered by one of Prime Minister Benjamin Netanyahu's top aides.

As an apparent incentive to Palestinian leaders to intervene, Israel pledged to proceed with this month's transfer to the Authority of around $100 million in tax revenues that it collects on its behalf.

Israel began withholding the funds, money the Palestinian Authority badly needs to pay public sector salaries, after Abbas secured UN de facto recognition of Palestinian statehood in November.

Under international pressure, Israel announced it would release $100 million to the Palestinian Authority last month.

Prisoners affiliated with Hamas issued a call for a new Palestinian uprising.

Amos Gilad, a senior Israeli Defense Ministry official, questioned whether the protests were just a tactical move by the Palestinians to draw international attention before Obama's visit to Israel, the West Bank and Jordan.

But he added, in an Israel Radio interview: "Things can get out of control."

Yasser Abed Rabbo, a senior Abbas aide, said Israel's treatment of prisoners and anti-Palestinian violence by Jewish settlers were "the cause of the deterioration".

Israel said it would carry out an autopsy of the body of Jaradat. Israel's Prisons Authority said he had not been on a hunger strike and had been examined by an Israeli doctor during an interrogation on Thursday.