scientific experiments demonstration gone wrong (role of hydrogen unclear)

Around 60 people gathered in a small theatre at a shopping centre to watch an array of scientific experiments, including a "small hydrogen explosion."
Several children suffered second degree burns with children aged between five and 13 rushed to the nearest hospital.
It remains unclear which chemicals were used in the experiments, with some reports claiming both hydrogen and alcohol-based chemicals were used.
However a statement released by the Russian investigative committee examining the case said the science show had used "liquid nitrogen".
The "flammable" substance was then ignited by the gas burner, resulting in the explosions.
Meanwhile local authorities are investigating whether a breach in safety standards led to the incident.

It is unclear which chemicals were used in the experiments: hydrogen and/or alcohol-based chemicals.
The statement released by the investigative committee examining the case said the science show had used "liquid nitrogen", which is obviously nonsense.
The "flammable" substance was then ignited by the gas burner, resulting in the explosions.

scientific apparatuses

In footage captured of the incident, children can be seen running from the room in flames as another explosion bellows out.
Several children suffered second degree burns with children aged between five and 13 rushed to the nearest hospital.

The technical director of the company responsible for renting spaces at the shopping centre has since been arrested, alongside several organisers of the science show.
Meanwhile local authorities are investigating whether a breach in safety standards led to the incident.