The head of the Palestinian Authority committee against the separation wall and settlements died Wednesday after Israeli soldiers assaulted him in a village near Ramallah on Wednesday in a protest.
Ziad Abu Ein was killed near Ramallah, Palestinian Maan news agency reported.
The Fatah official was attacked by an Israeli soldier while planting an olive tree with activists in Turmsayya village near Ramallah.
An Israeli soldier hit Abu Ein on the chest with his helmet and fired teargas at him and other activists.
Abu Ein, who suffered asphyxia from heavy tear gas inhalation, lost consciousness and was transferred to Ramallah hospital, where he died at noon.
A member of the Revolutionary Council of Fatah, Abu Ein announced on Tuesday via Facebook that he would participate in the protest.
Palestinian President Mahmoud Abbas condemned the killing of Abu Ein as "barbaric," and announced three days mourning.
"We will take necessary measures after the results of an investigation into the incident are known," Abbas said.
In recent months, East Jerusalem has been hit with tensions due to Palestinian fears over allowing Jewish prayers at Al-Aqsa mosque. There have been fierce clashes between Palestinian protesters and Israeli forces. Al-Aqsa mosque is regarded as the third holiest site for Muslims.
Tel Aviv's settlement plans represent another cause of unrest. On 3 November, Israel's interior ministry approved the construction of about 500 new settlements in occupied East Jerusalem. One month earlier, Israel's Premier Benjamin Netanyahu vowed to build more than 1,000 new settler homes.
The Palestinian Ministry of Foreign Affairs condemned Israel's "daily war against Jerusalem, its holy places, Palestinian citizens and their property."
In a press statement, the ministry denounced the frequent storming of Al-Aqsa mosque by Israeli occupation forces and "Jewish extremists."
"The ministry emphasises that the continuation of the Israeli government’s efforts to organise, finance and encourage these policies signifies its persistence in pushing for a religious war," said the ministry, pointing out that Israel is "rebelling against" international law and calls for an end to its "provocative settlement activities."
The ministry also condemned Israeli arrest campaigns against children, youth, women and old people in Jerusalem, describing them as a "violation of the Geneva conventions and international humanitarian law."