The phenomenon known as the Naga fireballs (bang fai phaya nak) also known as the Mekong lights
The fireballs are most often reported around the night of Wan Ok Phansa at the end of the Buddhist Lent in late October.
Naga fireballs have been reported over an approximately 250 kilometre long section of Mekong river with the center of this section approximately at Phon Phisai town in Amphoe Phon Phisai.