'Pratibha Cauvery,' along with several ships berthed at the Chennai Port, was yesterday asked to go to the Outer Anchorage (OA) of the port as a precautionary measure before the severe cyclonic storm arrived, they said.
However, the ship, anchored about 3.56 nautical miles away from the Port yesterday, drifted and touched the shore near Elliots Beach.
"The ship was carrying 37 people on board," the sources said, adding that 15 of them tried to escape by life boat but were left stranded in the sea as the vessel capsized.
"So far four persons have been rescued. Coast Guard is coordinating with us", the sources said.
The 26,000 tonne capacity tanker had two tonnes of light diesel and furnace oil when the mishap occurred.