This is the moment a heroic passerby saved a five-year-old boy being swept away by a swollen river after heavy rain in Thailand.

An unidentified man was passing by the bridge when he saw the frantic locals shouting at the youngster in the middle of the muddy deluge in Phetchabun province on September 3.

He then climbed down the hill to help the helpless boy sitting in the middle of the water before grabbing a huge stick to let the boy hold on to it.

As the boy grabbed the stick, he dragged it to the riverbanks and took the exhausted youngster up to the ground safely.

Onlooker Nuiy Kanphatsawee said: ‘I hope this will set an example for parents to watch over their children closely. Do not let your children play in the water as it’s the monsoon, so the canals and rivers are not safe.’

Nuiy added that the boy was playing in the water with a friend when there was a sudden flash flood and trapped the boy in the middle.

She said: ‘The boy was playing with his friend. The rain had stopped so they thought it was already safe but the water rose after a flash flood.’

The boy thanked the man who left after saving him before he was taken home by neighbours after the incident.

Thailand and other countries in Southeast Asia such as Malaysia, Indonesia and the Philippines are in the middle of their tropical monsoon rainy season, which lasts until October or November. Soaring temperatures reaching 35 degrees Celsius are often followed by powerful tropical storms with thunder, lightning, rain and flash floods which cause rivers to flow faster and become dangerous.