Thousands of locals join the annual Songkran water fight festival celebrations in Khon Kaen, northeast Thailand, on Sunday night.

The Buddhist festival Songkran, which takes place every year from April 13 to April 15, marks the new calendar year in the ancient religion. It originated in India in the 6th century before being taken up by the Hindu-Buddhist Khmer Empire - the predecessor to modern-day Cambodia.

Followers splash each other with water to wash away the sins and bad luck of the past year. Traditionally, young relatives would pour water over the hands and feet of elders as a mark of respect.

However, the once-sedate festival has been commercialised by the avaricious Thai tourism industry and spawned into large water fights across the country's major cities, with hundreds of thousands of tourists joining in the chaos to cool off as temperatures reach 40 degrees Celsius in the hottest month of the year.

Ministers have urged locals not to drink and drive while officials in Bangkok have banned alcohol at its official festival venues due to the rise in road accidents during the period.

There are also criticisms that it wastes water at a time when prolonged droughts are causing peril across the world.