Israeli police have opened an investigation into threats on social media against President Reuven Rivlin following his condemnation of "Jewish terrorism" after a firebombing killed a Palestinian child, a presidential spokesman said Monday.

Rivlin had written a Facebook post following Friday's arson attack on a Palestinian family's home in the West Bank village of Duma by suspected Jewish extremists.

A teenager stabbed at a Gay Pride march died of her injuries Sunday as the attack and a firebombing that killed a Palestinian child put pressure on Israel to crack down on Jewish extremists.

Shira Banki, 16, was among six people stabbed at the Jerusalem march on Thursday by a suspect identified as an ultra-Orthodox Jew released from prison only weeks earlier for a similar attack. 

Clashes broke out on Sunday at Jerusalem's Al-Aqsa mosque, one of Islam's holiest sites, two days after a Palestinian toddler was burned alive in a firebombing by suspected Jewish extremists.

Police said masked Palestinian youths at the mosque threw stones at security forces while protesters held aloft photographs of the 18-month-old child killed in Friday's arson attack in the occupied West Bank.

The parents and brother of a Palestinian toddler burned to death by suspected Jewish extremists were fighting for their lives on Saturday, as protests over the arson attack entered a second day.

The firebombing of the family's home in the occupied West Bank, which killed 18-month-old Ali Saad Dawabsha, sparked an international outcry over Israel's failure to get to grips with violence by hardline Jewish settlers.

A Palestinian teen shot during clashes with the Israeli army in the West Bank died of his wounds early Saturday, Palestinian medical and security sources said.

The sources said 14-year-old Laith Khaldi of the Jalazon refugee camp was shot in the chest during clashes with Israeli forces near the Atara checkpoint on Friday evening and died hours later in hospital.

An ultra-Orthodox Jew accused of stabbing six people at a Gay Pride march in Jerusalem weeks after his release from jail for a similar attack lashed out in court Friday, Israeli media reported.

"I do not accept this court's authority," said a defiant Yishai Shlissel, representing himself at a hearing.

The EU urged Israel Friday to show "zero tolerance" for settler violence after an arson attack blamed on settlers in the occupied West Bank left a Palestinian toddler dead.

"The Israeli authorities should ... take resolute measures to protect the local population. We call for full accountability, effective law enforcement and zero tolerance for settler violence," a spokesperson for EU foreign affairs head Federica Mogeherini said in a statement.

A Palestinian toddler was burned to death and four family members wounded in an arson attack by suspected Jewish settlers on two homes in the occupied West Bank on Friday.

Israeli Prime Minister Benjamin Netanyahu called the firebombing in the village of Duma near the northern city of Nablus "an act of terrorism in every respect" and ordered security forces to hunt down the perpetrators.

Israel has deployed the Iron Dome defense system to the north on the border with Lebanon, likely amid fears that Hizbullah could get an infusion of cash and weapons from Iran after the nuclear deal.

In an exclusive interview with FoxNews.com, the commander of Israel’s Active Defense Air Wing, Col. Yoni Saada Marom, said that the military drills were not a direct reaction to recent events, but made clear that Hizbullah and other groups close to Israel's borders presented a potentially heightened threat.

An ultra-Orthodox Jew allegedly stabbed six Gay Pride marchers in Jerusalem Thursday, gravely wounding one of them, just weeks after completing a 10-year sentence for a similar attack, police and medics said.

The assault occurred in Jerusalem's city center, with witnesses describing terrifying scenes of an assailant, dressed in ultra-Orthodox garb, storming the parade with a knife.