The incident occurred due to leakage of an LPG cylinder, a senior official told PTI.
He said the injured have been rushed to hospital, where the condition of six was stated to be serious.
Fire engines were rushed to the spot and the flames were brought under control, he added.
This was the first such incident after the Maha Kumbh Mela, often described as the "greatest show on earth", began on the confluence of Ganga, Yamuna and the mythical river Saraswati on January 14 on Makar Sankranti.
Held every 12 years, it will conclude on Maha Shivratri on March 10.