Ramallah: A senior Palestinian official died on Wednesday after being beaten by Israeli forces during a protest march in the West Bank, medical and security sources told AFP.
Palestinian president Mahmud Abbas condemned the "barbaric act" and vowed measures in response.
Ziad Abu Ein, who was in charge of the issue of Israeli settlements for the Palestinian Authority (PA), "was martyred after being beaten in the chest," said Ahmed Bitawi, the director of the Ramallah hospital.
A Palestinian security source told AFP that Israeli forces beat Abu Ein with the butts of their rifles and their helmets during a protest march in the village of Turmus Ayya near Ramallah.
An AFP photographer said Israeli soldiers had fired tear gas as Abu Ein participated in a march of some 300 Palestinians who intended to plant olive trees.
Three soldiers grabbed Abu Ein and hit him in the chest, the photographer said. Abu Ein fell and an Israeli army doctor rushed to treat him before he was evacuated to hospital.
Another witness, Kamal Abu Safaka, said that Abu Ein was "beaten by a soldier" in the chest "after having a conversation with the officer in charge."
The Israeli army had no immediate comment.
Abbas condemned "the brutal assault that led to the martyrdom" of Abu Ein, calling it "a barbaric act that cannot be tolerated or accepted," official Palestinian news agency WAFA said.
"We will take the necessary measures after the results of the investigation into the incident," Abbas said, declaring three days of mourning.
The Islamist movement Hamas, the de facto rulers in the Gaza Strip, issued a statement mourning Abu Eid's death and calling on the PA to cease security coordination with Israel.
"The time has come to rally all our forces in facing the criminal Zionist occupation and stop all sorts of security coordination with the occupation," it said in a statement.
Abu Ein, 55, has previously been arrested and imprisoned by Israel.
He was extradited from the United States in 1981 over the murder of two Israelis in Tiberias in 1979, and sentenced to life in prison, but released in 1985 in a prisoner exchange.
Besides his role in the PA monitoring Israeli settlements and the separation barrier, Abu Ein was a member of the Fatah Revolutionary Council and previously served as deputy Palestinian minister for prisoner affairs.