Ten persons were injured in a fire that broke out in one of the shops at the Mattuthavani Integrated Bus Stand on Thursday evening.
While three had been admitted to the Government Rajaji Hospital, seven others were treated as outpatients, the police said.
This was the second fire accident at the bus stand in less than a fortnight.
The fire broke out at a shop while people were making savouries, the Tallakulam Station Fire Officer, E. Balasubramanian, said.
Though eyewitnesses said there was a loud explosion few minutes after the fire broke out, the SFO said there was no possibility for burst of cooking gas cylinder.
“The sound of explosion could have been due to burning of live electric wire,” he said.
The cause of fire was yet to be ascertained, he added.
A flower vendor, Mahalakshmi, who was seated outside the shop on the margin of city bus bay, said she had fled the scene on seeing the fire.
Few people, including autorickshaw drivers, who tried to help the shop-keepers in removing the articles, were injured in the blast.
“Fellow onlookers had to tear open the shirt of one of them after it caught fire,” she said.
While the savouries shop was completely gutted, three adjacent shops – a tea stall, a footwear shop and a fancy store, had collateral damage.
Three fire tenders were pressed into service to put out the fire.
One of the witnesses at the accident site said that luckily the city buses parked bang outside the shop were moved in time to safer distance. “Had it exploded immediately, the damage could have been to a greater extent,” he said.
City buses and mini buses were diverted for nearly an hour to enter and exit the bus stand through the exit gate so as to keep them away from the inferno.
Five shops were gutted in the fire that broke out in the bus stand on July 21.