A family of five Jewish settlers, including three children, was stabbed to death Friday night near the West Bank city of Nablus, ending a relative lull in deadly violence in the Palestinian territory.
Two other small children escaped harm by hiding as unknown attackers apparently sneaked into the family's home with a knife and killed the parents and children, ages 12, 3 and 3 months.
It was the deadliest such attack against Jewish settlers in the area since 2002.
Israeli military officials immediately declared the Itamar settlement and surrounding Palestinian villages to be a closed military zone, setting up roadblocks and launching a massive search for the attackers.
Israel Defense Forces Maj. Gen. Avi Mizrahi vowed to catch the "despicable, cowardly murderers who came in the dead of night and murdered children, a mother, a father. We are in pursuit of the perpetrators and I estimate we will get our hands on them before long."
No one has claimed responsibility for the attack, but Israeli authorities suspect the killings were part of a terrorist strike by Palestinian militants. In the past, Palestinian militants have defended attacks against Jewish settlers living in the West Bank, calling them combatants rather than civilians.
Founded in 1984, the Itamar settlement has a population of about 1,000, including many ideological and religious families who advocate that Israel absorb the West Bank, which Israel seized during the 1967 Mideast war.
Most of the international community considers Israel's occupation of the West Bank illegal and have called for settlements to be removed.
Relations between residents of Itamar and surrounding Palestinian villages have been poor for years, with frequent attacks and counterattacks.