A blast from a homemade bomb killed one Israeli and seriously wounded two of her family members in an attack near a Jewish settlement in the occupied West Bank on Friday, officials said.
Israeli security forces were deployed throughout the area of the attack near the settlement of Dolev, northwest of Ramallah, in a search for suspects.
Israeli medics had earlier reported that a 17-year-old had been critically wounded in the attack. President Reuven Rivlin and her hometown of Lod in central Israel both announced her death.
Medics from the Magen David Adom rescue service gave the ages of the two others as 46 and 20. Israel's army said the victims were a father and his two children.
The two other victims were taken by helicopter to a hospital, the army said.
"Three civilians who were in a nearby spring were injured in an IED blast," the army said in a statement.
Further details were not yet available on the incident.
Palestinian attacks on Israeli settlers and security forces occur sporadically in the West Bank, occupied by Israel since the Six-Day War of 1967, but bomb blasts have been rare in recent years.
There have been concerns of a possible increase in violence in the run up to Israel's September 17 general election.
A week ago, a Palestinian car-ramming attack in the West Bank wounded two Israelis, while the assailant was shot dead.
On August 8, an off-duty Israeli soldier's body was found with multiple stab wounds. Two Palestinian suspects were later arrested.