Beachgoers collected thousands of ponyfish that washed up on the sand in Thailand.

Footage shows tourists helping locals clean up the tiny silver water animals that lined the shore of Patong Beach in Phuket on October 11.

They put the fish in trash bags before they start to rot and attract flies to the destination.

A local said they saw a school of ponyfish swimming near the shallows a day before the beaching happened.

Jamnong Samli said: 'There was so much dead fish in Patong Beach that day.'

Authorities arrived to do a clean-up and investigate the cause of the fish kill.

Fish may get trapped in shallow waters during low tide or be washed ashore by strong waves and storms, especially during the monsoon season. Sudden changes in water temperature, such as a rapid rise or fall, can also disorient them, causing them to wash up on beaches.