The Israeli army announced a Palestinian city in the West Bank a closed military zone following the killing of five settlers in a nearby Jewish settlement, Palestinian witnesses said Saturday.

The Israeli forces installed more checkpoints on the roads leading to Nablus city and prevented Palestinian vehicles and pedestrians from entering or leaving the city, the witnesses said.

The army also broke into Burqa village in northern Nablus and started searching houses and questioning residents. The troops did not arrest any villager.

The closure come hours after unknown assailants broke into a house in the nearby Itamar settlement and stabbed to death five Israelis.

The suspects managed to escape after killing the parents and three children aged between three months and 11 years, Israel Radio reported.

In 2002, a Palestinian armed with rifle broke into a house in the same settlement and killed a woman and her three children.

Israeli settlements have always been on the Palestinian negotiation agenda, and caused the U.S.-brokered peace talks to halt in September after Israel ended a 10-month moratorium on construction in the West Bank's Jewish settlements.