JERUSALEM, April 30 (Xinhua) -- At least 38 people were killed and 100 others injured in an apparent stampede at an overcrowded Israeli festival after midnight Thursday, local media reported.

The tragedy happened on Mount Meron in northern Israel. The specific cause was not immediately clear, but initial reports pointed to a stand collapse at a concert.

Israeli ambulance service Magen David Adom tweeted that it was treating 50 people, including 20 in critical condition.

Citing the massive size of the gathering, rescue authorities said they struggled to evacuate the trapped people, according to Haaretz daily.

Six helicopters have been dispatched to the scene to evacuate the injured and a field hospital has been set up.

According to police sources, the stampede occurred after some revellers slipped on steps, causing more people to fall over.