The explosion took place at around 7 AM when the workers at the private unit, where toys are made out of Plaster of Paris (PoP), were diluting an outdated chemical with water near a gas cylinder kept in the premises, Karimnagar Deputy Superintendent of Police J Rama Rao said.
While doing so, the chemical, due to some reaction, exploded and subsequently there was also a blast in the gas cylinder kept nearby, killing two workers, he said.
Another worker who sustained serious injuries in the mishap was shifted to district headquarters hospital in Karminagar, where his condition was reported to be critical.
Police registered a case and were further investigating, Rao added.