After a number of smartphones were thrown onto a Lag B’Omer bonfire in London’s Stamform Hill, home to a huge community of ultra-Orthodox Jews, a massive explosion occurred, injuring as many as 30 people, mostly children.

The explosion, according to this report, occurred around 10 pm on Wednesday night near the Biala Shul in Stamford Hill, after a rabbi lit the bonfire. The photo above shows one of the victims being treated for facial injuries.

Multiple Smartphones had been dropped into the pile of rags prepared for the bonfire, as a statement against the “spiritual corruption” borne by smartphones and the Internet.

The rabbi reported spoke about the evils of the smartphone just before igniting the bonfire, and as soon as the fire was lit, there was a Massive Explosion and a large fireball.

This report added that medics treated about 30 people at the scene, and some 10 were taken to local hospitals with burns on their faces.

Footage of the explosion distributed by Hatzola, a Jewish volunteer emergency medical service, showed a local ultra-Orthodox rabbi preparing to light a pyre. When he tried to ignite it, however, the pile immediately erupted in flames and sends dozens of people fleeing in panic.

London’s ambulance service said it sent a hazardous area response team to assist Hatzola.

The festival of Lag B’Omer marks the anniversary of the death of Rabbi Shimon bar Yochai, a 2nd century CE sage. The custom of lighting bonfires to celebrate it has developed over the past hundreds of years and has no basis in religious law.

In Israel, many bonfires were lit for Lag B’Omer despite multiple warnings to refrain from doing so issued by the Israel Fire and Rescue Services, the Health Ministry and even Prime Minister Benjamin Netanyahu – and the fire services had to deal with a number that got out of control.