In a crush at a packed religious celebration in Israel's north-east, at least 44 people were killed.
At the annual Lag B'Omer event at the foot of Mount Meron, dozens more people were hurt.
Prime Minister Benjamin Netanyahu visited the area and declared Sunday a national day of mourning.
The all-night festival drew tens of thousands of Orthodox Jews, making it Israel's largest gathering since the coronavirus outbreak began.
Many restrictions have been lifted as a result of the country's successful immunisation programme, but health experts have warned about the risk of Covid-19.
'People were catapulted up in the air,' said witnesses.
Initially, it appeared that a structure had collapsed at the site, but emergency personnel later stated that a crush had occurred at around 01:00 local time (22:00 GMT Thursday).
In a crush at a packed religious celebration in Israel's north-east, at least 44 people were killed |
According to police sources, the incident began when a few attendees tripped on the steps, causing hundreds more to fall.
It all happened in a flash; people were trampling one other. One witness told the newspaper, "It was a disaster."
Thousands of people are seen attempting to flee down a tight corridor in videos released online.
Before police sought a thorough evacuation of the venue, loudhailer broadcasts urged the people to disperse.
No one expected this to happen here," one pilgrim told Channel 12 television. "A vast brightness became a deep gloom, and rejoicing became grief.
Several ambulances arrived on the site, and emergency personnel laid bodies out on the ground under foil coverings. Helicopters transported the injured to hospitals, and search-and-rescue teams were also sent, according to the military.
Officials reported at least 150 individuals were hurt, with 38 of them in critical condition on the scene.