Bathinda, June 2 -- The Muktsar police are questioning the father-son duo arrested in the cracker factory blast to know how they managed to source explosive materials even though they did not have a license to operate the unit.

Owners of the illegal factory Tarsem Singh and his son Navraj Singh were produced in the sub divisional court at Malout on Saturday evening.

Lambi deputy superintendent of police (DSP) Jaspal Singh said the court sent them to four-day police remand.

"The third accused, Raj Kumar, a labour contractor, will be produced in the court on Monday," said the DSP.

Five migrant workers were buried alive and 28 others sustained injuries after an illegal factory at Fatuhiwala was razed due to an explosion.

Investigators a...