Thirty-seven people were injured, many of them seriously, when a homemade rocket failed to launch and exploded amongst the watching crowd in Roi Et on Sunday evening.
The traditional rain-seeking rocket, known as Bung Fai, first exploded on its launching stand after being ignited about 5pm on Sunday.
It then flew off to the side and into the crowd, and exploded again.
Rescue workers rushed the injured to hospital. They suffered from injuries to their heads and limbs. Some were either unconscious or had fractured limbs, ribs or skulls.
Witnesses said the second explosion as the rocket ploughed straight into the crowd caused most of the injuries.
Bung Fai rockets are traditionally launched at this time of year to seek rain from a deity. They are also launched in contests, judged by the time they remain airborne, and are made largely from PVC pipe.