Assistant superintendent of police Anoop Kumar said a raid was conducted by an official team headed by assistant district magistrate (city) Preeti Jaiswal, officials of electricity and labour department.
During the three-hour operation, 20 factories were thoroughly examined and six of them were sealed for violation of laws even as raw and finished material was also seized from them, the ASP said.
The raiding team broke open the gates of 10 illegal factories by breaking their locks and impounded the goods, the police officer said, adding electricity connections of 18 units were also disconnected.
He said such raids will be conducted in future and strict action would be taken against those illegally running factories here.
On November 10, a rexine factory was gutted into flames in Shaheed Nagar colony of Sahibabad area and 13 people were killed due to suffocation and stampede.