An 18-month-old Palestinian boy has burned to death after settlers set fire to his family house in Duma village, south of Nablus city, in the occupied West Bank.

The parents of Ali Saad Dawabsheh and his four-year-old brother were also injured in the attack, sources told Al Jazeera on Friday morning.

Up to 75 percent of their bodies suffered burns, according to medics in Nablus' Rafidia hospital.

The Israel army issued a statement saying that they were trying to 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.

"The [Israeli army] strongly condemns this deplorable attack and has heightened its efforts in the field to locate those responsible."

The army told Al Jazeera that additional forces were deployed to West Bank, refusing to specify the number of soldiers.

PM Netanyahu issued the following statement in wake of the murder of Ali Dawabshe: "I am shocked over this reprehensible and horrific act." — PM of Israel (@IsraeliPM) July 31, 2015

Palestinian reaction

Mahmoud Abbas, the Palestinian president, said on Friday that he wants the International Criminal Court to probe the attack as one of the first Israeli war crimes against Palestinians.

"Every day we wake up to a similar crime. This is a war crime and a tragedy at the same time. Therefore we will not stay still. Absolutely not. As long as the settlement and the occupation are there," Abbas said.

Nabil Abu Rdeineh, a spokesman for Abbas, said earlier on Friday that the Israeli government was fully responsible for the crime as it continued to support illegal Israeli settlement activities and the protection of settlers.

He also blamed the international community for silence over crimes against Palestinians.

Abu Rdeineh said that verbal condemnation of the crimes was no longer acceptable and that taking practical steps to hold Israeli attackers accountable, as well as the end to the occupation, was needed.

The Palestinian Liberation Organization (PLO) that is led by Abbas reacted to the attack on Twitter.

This is a direct consequence of decades of impunity given by the Israeli government to settler terrorism pic.twitter.com/krEg7IAVqe — Palestine PLO - NAD (@nadplo) July 31, 2015

Two Palestinian houses were burned at the entrance of the village with graffiti left on the walls, reading in Hebrew "revenge" and "long live Messiah".

Witnesses told Al Jazeera that they saw at least two settlers running away from the scene.

Lars Faaborg-Andersen, the European Union envoy to Israel also reacted on Twitter.

Deeply shocked by murder of baby Ali Darawshe, presumably by extremist settlers.Terrorists must face justice. Urge calm on all sides.- LFA — EU in Israel (@EUinIsrael) July 31, 2015

There are at least three illegal Israeli settlements near Duma village.

According to the UN, at least 120 attacks by Israeli settlers have been documented in the occupied West Bank since the start of 2015.

A recent report by Yesh Din, an Israeli human rights organisation, showed that more than 92.6 percent of complaints Palestinians lodge with the Israeli police go without charges being filed.