Israeli doctors say at least three people were killed in a knife attack near Tel Aviv on Thursday night.
Police said they suspected it was a militant attack and the attacker fled in a vehicle.
Security forces erected roadblocks in the area around which the killings took place, in the town of Elad, and a helicopter could be seen hovering over the area.
The Magen David Adom emergency service said three people were killed and four others injured; two of the injured were in serious condition.
Israel celebrated its Independence Day on Thursday, a festive national holiday when people typically have barbecues and watch air shows.
The identity of the attacker was not yet known. But Israeli-Palestinian tensions have skyrocketed in recent weeks, following a series of bombings in Israel, military operations in the occupied West Bank and violence at an important holy site in Jerusalem, sacred to Jews and Muslims.