The London Fire Brigade has issued safety guidelines to the strictly Orthodox community in Stamford Hill ahead of this week’s Lag Ba’Omer fire celebrations, after an explosion at last year’s event injured dozens of people.

In a notice circulated around the Jewish community in Hackney, the LFB asked people to “take extra care when celebrating" on Wednesday night, "following numerous calls to bonfires within the Stamford Hill area last year.”

The fire brigade’s borough commander for Hackney, Narinder Dail, said last year was busy for local fire crews “as they attended seven reports of bonfires which we believe were lit as part of the festivities.

“Thankfully, none of the fires spread to cars or buildings, but we are concerned that there could be a more serious fire this year.”

An explosion which took place at a bonfire in Stamford Hill last year injured a number of people, with further injuries caused as a crowd of people fled from the blaze.

Reports suggested the explosion may have been caused by the fuel which had been thrown on the bonfire before it was lit or by smartphones which had been placed on the bonfire.

None of the injuries were serious.

The use of smartphones or any phones with internet access is condemned by some strictly Orthodox religious authorities.

However, the batteries inside the smartphones may have exploded when they were tossed into the flames.

“There were lots of videos on social media which seem to show the fires flashing and exploding which suggests that people may have been using accelerants,” Commander Dail said.

She urged people to “never throw anything like aerosols, batteries or petrol onto a fire. We want the community to celebrate in safety.”

Orthodox Jews around the world have the custom to light bonfires on Lag Ba'Omer, with the festival said to mark the anniversary of the death of a great sage, Rabbi Shimon bar Yochai, who is said to have brought light into the world through his authorship of the Zohar, an ancient Kabbalistic work.

The main fire is lit in Meron, Israel, at the tomb of Rabbi Shimon, with hundreds of thousands of people attending each year.