A K Mishra, chief inspector of factory, Jharkhand said that the injured were admitted to the Tata Main Hospital here, where the condition of one was stated to be serious.
He said the deceased has been identified as M K Dey.
Officer-in-charge of Gamariah Police Station A Mahato confirmed the incident.
Mishra said that the cause of the explosion is yet to be ascertained.
Usha Martin authorities could not be reached for comment on the incident.