Thousands of sea cucumbers were found dead after being washed up on a beach in Thailand following heavy rain.

Shocked fishermen found the tiny creatures, also called sea slugs, next to a village in Chanthaburi province on October 22.

Locals rushed to throw save those that were still alive by throwing them back into the sea, but most of them were already dead. There was also pollution and ocean trash that washed up together with the marine animals on a 300 metre stretch of beach in the Laem Singh district.

Fisherman Wipphat Lippayakorn, 35, said they were about to prepare their boats when they saw the tiny creatures scattered all over the wet sand.

He said: "We were heading for the beach to our boats when we saw the sea cucumbers. Some of them are still alive so we returned them to water.

"I think it's the garbage that killed them, there's no other reason they will die in huge numbers like that."

The incident was reported to the local officials who relayed the information to their marine centre.

Tests have found low salt content in the water due to freshwater from monsoon rains creating a temporary imbalance. This then likely to have killed the sea slugs and they were washed ashore.

Sea cucumbers are marine animals with a leathery skin and an elongated body resembling the vegetable where its name was derived. They are usually found on sea floors worldwide.