Kanpur,  Three labourers died after inhaling poisonous gas while cleaning a septic tank near a tannery here.

The incident took place near Shalimar tannery in Jajmau area.

According to reports, the three fell unconscious and the tannery staff rushed them to Hallett hospital where the doctors declared them brought dead.

The staff then fled the hospital and the police was called in.

"We are investigating the case and efforts are being made to identify the labourers and also inform their families," said a police official.