Witnesses said the driver of the tanker lost control of the vehicle as he was trying to negotiate a sharp bend.
The accident came just hours after four other people of the same family were killed in another accident at Kadongo Trading centre in Rachuonyo East.
Three people died in a second road accident in Homa Bay County involving a motorcycle and a fuel tanker along the Oyugis-Gamba road in Oyugis Town in Rachuonyo South Sub-county, on Tuesday night.
The deceased were a rider and his passengers who were travelling towards Oyugis Town a few minutes before 8pm.