Visitors fed a shoal of catfish, causing the water to churn as the fish scrambled for bread thrown from a boat.

Footage shows a crew member handing bags of bread to holidaymakers in life vests on the Chao Phraya River in Bangkok, Thailand.

The tourists can be seen tearing the bread into small pieces and tossing them into the water, triggering a feeding frenzy as the creatures surfaced to grab the treats on January 25.

The high number of catfish in the Chao Phraya is largely due to the Buddhist tradition of releasing fish to gain spiritual merit.

These fish congregate in sanctuary zones near temples where fishing is strictly prohibited, allowing them to remain protected. They also thrive thanks to the constant supply of food from tourists and their natural ability to survive in murky, low-oxygen water.