A huge bunch of balloons burst into a ball of fire after sparks from firecrackers punctured them just before release during Prime Minister Narendra Modi's weeklong birthday celebrations here injuring a number of people, police said on Saturday.

The incident occurred when BJP members, all set to release the balloons, burst firecrackers while garlanding a farmers wing state level office-bearer, Muthuraman at Padi on Friday.

The BJP is celebrating Modi's birthday (September 17) as "Seva Diwas" for a week.

Sparks, that emanated from the crackers punctured the balloons and in a trice they burst into a huge ball of fire, prompting party workers to take to their heels and the blaze dissipated in moments, police said.

The BJP members had planned to release a hundred hydrogen filled balloons into the air and the mild explosion caused burn injuries to a number of people who were admitted to the Kilpauk Medical College Hospital for treatment, they said.

Tamil Nadu BJP unit president L Murugan visited the injured at the KMCH, a renowned government institution for treating burns here, and requested the hospital authorities to provide necessary treatment.

Murugan interacted with the injured and consoled them.

Since the event was held without permission, the Korattur police booked a case against the organisers and a brief video of the freak accident went viral in social media.

While the party cadres were holding hundreds of balloons filled with hydrogen gas, sparks from firecrackers hit some balloons and in no time all balloons burst leading to a fire, police said.

Meanwhile,a case was booked against Murugan and others for taking out a "chariot ride" in violation of prohibitory orders clamped in view of the coronavirus pandemic and for alleged "unlawful" assembly.

Also, a case was registered for putting up illegal banners, they added.