Five people including three children were injured when a cylinder used to fill balloons exploded in Madhya Pradesh's Ujjain.
The police said a balloon seller was filling air at a crowded New Year fair when the incident happened.
Many children had gathered around him to buy balloons, the police said. The condition of one of the injured children, who is eight years old, turned critical. He was taken to a hospital in Indore for advanced treatment. The rest are being treated at a local hospital.
The explosion was so intense that walls near the fair were damaged.
Local official Preeti Gaikwad said the accident happened due to wrong mixture of hydrogen gas in the cylinder. The parts of the damaged cylinder have been sent to a laboratory for investigation.
"I was setting up my shop when the blast happened," the balloon seller, Altab Shah, said. He was also injured.
The fair was organised by a local politician amid the COVID-19 threat.
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