"Several people died in Pingla. We have ordered a CID investigation into it," she said during a programme here.
"How could so many firecrackers be prepared at one place and how so many explosive substances were accumulated in one place ?" Banerjee asked.
"I ask all Green police (civic police) personnel in all villages to keep a watch on such activities and to inform the local police station if they find explosive substances being accumulated at any place," she said.
She also asked the media to keep an eye on any untoward activity and share information with the authorities.
Eleven people were charred to death and four others injured in an explosion at Pingla in West Midnapore district late last night. Police said the factory was illegal.