Six bodies (all males) were taken out and sent to mortuary for identification, the senior IPS officer who was supervising the rescue operation told PTI over telephone.
Labourers were cleaning the chemical tank of a cloth factory when they probably got suffocated and could not come out, he said.
The reason behind the tragedy is yet to be ascertained, he said, adding that also the bodies are yet to be identified.
A rescue team was searching if any one person left into the tank, he added.