DUMA, West Bank, July 31 (UPI) -- An 18-month-old Palestinian boy died Friday after attackers believed to be Israeli extremists set fire to his family's house in the West Bank, law enforcement officials said.
The baby, Ali Saad Dawabsheh, was burned to death, and his parents and 4-year-old brother also sustained burns to between 70 percent and 90 percent of their bodies, medical officials at Rafidia hospital in Nablus, West Bank, told Al Jazeera.
The attack took place amid heightened tensions in the West Bank; Hamas had called for a "day of rage" and protests Friday for the recent killings of three Palestinians. Israeli police had also deployed extra officers in Jerusalem and restricted access to the al Aqsa mosque, where there was recently a disturbance, the Los Angeles Times reported.
Graffiti on the outside of the Dawabshehs' home read "revenge" and "long live messiah the king" in Hebrew.
Palestinian Authority President Mahmoud Abbas blamed the Israeli government for Ali's death, saying it supported Israeli settlement activities in the area. He blamed extremist Israeli settlers for the firebomb.
"What happened in Duma is added to a record of crimes committed by the settlers and the Israeli government, because it sponsors settlement activities and encourages settlers' actions," he said in a statement published by WAFA news agency.
Abbas said he intends to submit the case -- which he called a crime against humanity -- to the International Criminal Court.
The Israeli army said it intends to investigate Ali's death and locate the suspects in the attack.
"This attack against civilians is nothing short of a barbaric act of terrorism. A comprehensive investigation is under way in order to find the terrorists and bring them to justice," Lieutenant Colonel Peter Lerner said in the statement.
Israeli Prime Minister Benjamin Netanyahu said he was "shocked by the murder of Ali Dawabshe.
"This is a reprehensible and horrific act of terrorism in every respect," he said in a statement. "I have ordered the security forces to use all means at their disposal to apprehend the murderers and bring them to justice forthwith."
The attack comes on the heels of a report released by Amnesty International accusing Israel of war crimes against Palestinians during fighting in July and August 2014. The conflict resulted in the deaths of 135 Palestinian civilians, the report said.
"There is strong evidence that Israeli forces committed war crimes in their relentless and massive bombardment of residential areas of Rafah in order to foil the capture of Lieutenant Hadar Goldin, displaying a shocking disregard for civilian lives. They carried out a series of disproportionate or otherwise indiscriminate attacks, which they have completely failed to investigate independently," said Philip Luther, director of the Middle East and North Africa Programme at Amnesty International.
Six Israeli civilians also died in the two-month war, as well as more than 60 Israeli soldiers and more than 2,000 Palestinian fighters.
A U.N. report published in June suggests both sides of the conflict violated international humanitarian law and international human rights law.
When the Palestinian government joined the International Criminal Court in December -- a first step toward possible prosecution of Israel for alleged war crimes -- Netanyahu said it is the PA that should instead fear the international court.
He said the PA is "in a unity government with Hamas (which controls Gaza), a declared terrorist organization who, like ISIS (Islamic State), commits war crimes. We will deflect this further attempt to impose us with dictates, just as we deflected the Palestinian (resolution) at the U.N. Security Council."