Balloons exploded in a Chechen school on Last Bell

On May 23, at the solemn line in honor of the Last Bell in the village of Alleroy, the Chechen Republic, balloons filled with helium flared up.

Schoolgirls performed with helium balloons in their hands in the school yard. At some point, a smoke bomb was brought too close to the balls and they flared up. A fiery cloud unfolded over the schoolchildren for a few seconds.

Parents filming their children were able to film the incident. The sparks scared the hell out of everyone. Fortunately, there were no casualties, according to Mash.

In the comments, users suggested that the balloons were filled not with helium, but with hydrogen.

As far as I remember, helium is an inert gas, that is, it does not burn, is not explosive and is not toxic. But hydrogen and oxygen form an explosive mixture. So, apparently, the balls were pumped with hydrogen.