Went to Phon Phisai for the Naga fireballs. Locals will deck you if you call it methane.

Every year end of Buddhist Lent, full moon 11th lunar month (late Oct usually), the Mekong by Nong Khai does this. Bang fai phaya nak. Reddish balls rise straight up off the river surface, dead silent, go up a couple hundred meters then just wink out. No arc, no fall. Tens to thousands in a night de……