The Israeli military launched a massive search Saturday for suspected Palestinian militants after an Israeli family of five - including two young children and a baby - were knifed to death overnight as they slept in a West Bank settlement.
Footage from the scene broadcast on Israeli media showed children's toys covered in blood and furniture tipped over.
Israeli officials said Palestinian militants infiltrated the settlement and killed the couple and the children, ages 11 and 3. A baby also was killed.
Israeli media said two young children were asleep in another part of the house and survived. Another family member, a 12-year-old girl, was away at a youth group function when the attack occurred. She found the carnage when she came home and alerted authorities.
Military officials said they had made arrests, but wouldn't provide details.
"This was a very harsh terror attack, a whole family was wiped out by despicable cowardly murderers who came in the dead of night and killed innocent children, a woman and man as they slept," said Avi Mizrachi, commander of the military's Central Command.
The attack at Itamar settlement is the first against settlers in months and the deadliest in years, marking a rare outburst of violence during a relatively calm period. It comes as Israeli-Palestinian peace efforts are at a standstill and could complicate efforts to restart them.
Itamar is a small, isolated settlement in the northern West Bank that has rocky relations with the nearby Palestinian towns and villages.
Palestinian security forces also were searching for suspects, Nablus governor Jibril Bakri told The Associated Press.
Palestinian Prime Minister Salam Fayyad condemned the attack.
"Violence does not justify violence, we condemn it completely, whoever does it and whoever the victims are," Fayyad told the Associated Press.