An oil tanker ran aground on rocks while being battered by strong waves off a Thai island.

The 1,800-tonne Thai Laemthong 8 had finished delivering fuel to Cambodia when it suffered engine failure on its return trip to Rayong province. It was swept toward the rocky shores of Koh Mai Si island in Trat province, Thailand, on September 17.

Koh Kut district chief Phairat Soisaeng said authorities received a report at 7:30am. They found the vessel drifting in the rough sea with damage to its hull.

He said: 'We dispatched two fishing boats and requested a Navy ship to tow the tanker back into open waters. However, operations were difficult due to the poor weather and swollen waves.'

All 12 crew members were evacuated from the ship. They had earlier pumped out water to keep the Thai Laemthong 8 from sinking.

The ship had made an overnight stop between Koh Mai Si and Koh Kut islands to shelter from a storm on September 16 evening, before its engine died the following morning. There were no reports of oil leakage as the fuel had already been delivered to Cambodia.

Authorities said they were closely monitoring the situation, adding towing operations will continue when sea conditions become favourable.

Thailand and neighbouring countries in Southeast Asia are in their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms in the afternoon leading to widespread flash floods.