A senior Palestinian cabinet minister has died after clashes between demonstrators and Israeli troops during a protest in the West Bank.
Mahmoud Aloul, a leading member of Palestinian President Mahmoud Abbas' Fatah movement, said Ziad Abu Ein died shortly after the incident near the West Bank village of Turmus Aya.
Initial reports are conflicting, but one from the Associated Press quotes a witness who suggests the minister was hit by a tear gas canister. Another report, from AFP, quotes Ahmed Bitawi, director of the Ramallah hospital, saying the minister "was martyred after being beaten in the chest".
Abu Ein, a minister without portfolio in his early 50s, was rushed by ambulance from the scene, but died before reaching hospital in the nearby Palestinian city of Ramallah.
In a statement, Abbas called the death "a barbaric act which we cannot be silent about or accept". Announcing three days of national mourning, he said he would take "necessary steps" after an investigation.
A spokesperson for the Israeli military said it was looking into the incident.
It began as a march involving about 100 foreign and Palestinian activists headed to agricultural land near Turmus Aya to plant olive tree saplings, Aloul said.
The land belongs to Turmus Aya, but is close to an Israeli settlement and mostly off limits to the village's farmers, he added.
Witnesses said a group of around 15 Israeli soldiers fired tear gas at the protesters and began scuffling with them.
According to a Reuters photographer, Abu Ein was struck by a hand to the neck during an altercation with two of the soldiers, and was rushed away in an ambulance shortly afterwards.
Footage which aired on the Gulf news channel Hadath and could not be independently verified, appeared to Abu Ein crumpled on the ground pale-faced after the clash, holding his chest.
The Cabinet member headed a Palestinian Authority department dealing with Israeli settlements and the Israeli separation barrier. He had previously served as deputy minister for prisoner affairs.
The Palestinian Authority said it was weighing its response to the death, but the chief Palestinian peace negotiator and senior Abbas aide Saeb Erekat described it as an "assassination" that "will have severe consequences".
"The Israel government bears full responsibility for the killing of Minster Abu Ain and the systematic crimes committed against the Palestinian people," he said.
Osama Najar, a spokesperson for the Palestinian Health Ministry, said an autopsy would be performed to determine the cause of death.
Unrest in Jerusalem
Unrest in Jerusalem
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A masked Palestinian youth wearing a Hamas headband uses a sling-shot to throw back a tear gas canister towards Israeli forces during clashes outside the Israeli-run Ofer military prison following the deadly attack on a Jerusalem synagogue
Masked Palestinians hold axes and a gun as they celebrate with others an attack on a Jerusalem synagogue, in Rafah in the southern Gaza Strip
Israeli Zaka emergency services volunteers carry the body of one of the two Palestinian assailants who were shot dead while attacking worshippers at a synagogue to an ambulance in the ultra-Orthodox Har Nof neighbourhood in Jerusalem
An Ultra-orthodox jewish man prays at the scene of an attack, by two Palestinians, on a synagogue in the ultra-Orthodox Har Nof neighbourhood in Jerusalem
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An Israeli police officer gestures as he holds a weapon near the scene of an attack at a Jerusalem synagogue
Israeli Zaka emergency services volunteers carry the body of an assailant who was shot dead while attacking a synagogue
Israeli emergency services personnel clean the sidewalk at the scene of an attack, by two Palestinians, on Israeli worshippers at a synagogue in the ultra-Orthodox Har Nof neighbourhood in Jerusalem
Israeli security personnel run next to the synagogue in Har Nof, where a suspected Palestinian attack took place
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A Palestinian protester tries to hammer a hole through Israel's controversial barrier that separates the West Bank town of Abu Dis from Jerusalem
Palestinian protesters climb a ladder at Israel's controversial barrier that separates the West Bank town of Abu Dis from Jerusalem
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Masked Palestinian youths clash with Israeli security forces in the east Jerusalem neighbourhood of Abu Tor
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Israeli police officers walk at the scene of an attack in Jerusalem
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According to Palestinian security sources, shopkeepers in Ramallah have closed their stores in protest at the minister's death, while youths reportedly threw stones at Israeli soldiers guarding a Jewish settlement outside the city.