Two pilots died when a navy helicopter crashed late on Monday, the Israeli military said.
The helicopter was conducting a training flight off the Mediterranean coast when it crashed near Israel's northern city of Haifa.
A third crew member, an aerial observer, was moderately injured and taken to hospital, the military said on Tuesday.
“After extensive resuscitation efforts, the two pilots were declared dead," it said.
The pilots were named as Erez Sachyani, 38, and Chen Fogel, 27, both from northern Israel. Their families have been notified, the military said.
Authorities are investigating the cause of the crash.
The chief of the Israeli Air Force ordered the immediate suspension of all training flights and the use of helicopters from the same array as the doomed aircraft.
Israeli Prime Minister Naftali Bennett described the incident as a "very sad night".
The "pilots who perished in the accident were among the best of our sons. The people of Israel will not forget their contribution, night and day, for the security of the state", the premier said.
The US ambassador to Israel, Tom Nides, offered his condolences to the friends and families of those killed.
"I am also praying for a swift and full recovery of the other crew member who was injured," he wrote on Twitter.
A Haifa beach was closed on Tuesday as the search continued for parts of the helicopter, Israeli media reported.
Such accidents are relatively rare in Israel. In 2017, a pilot was killed in a helicopter crash during military training in southern Israel. A second pilot was seriously injured.