Rescue workers at the scene – some 60 miles north-west of the capital, Bangkok – said no survivors had been found.
The cause of the blast in Suphan Buri province is under investigation, but police confirmed there had been a previous explosion at the factory, in November 2022, in which one worker died.
The catastrophe happened less than a year after a large explosion at a fireworks warehouse in the south of the country killed at least 10 people and wounded more than 100, according to officials.
That explosion in Narathiwat province was in a residential area and damaged about 100 houses within a 500-metre (1,640ft) radius.
MP/PR
