With three more persons succumbing to injuries, the toll in the explosion at an unlicensed cracker unit at Thrnaliyil near Shornur town rose to 12 on Wednesday.
Doctors at the Medical College Hospital at Thrissur said two seriously injured labourers died this morning. Another victim had died last list.
Eight bodies were recovered from the blast site last evening and four were rushed to hospital.
Twelve labourers were engaged in making fire crackers at the unlicensed unit when the blast took place.
The unit, located in an open space close to Shornur-Palakkad railway track, has been functioning without licence for the last two years. A train had passed through the area when the blast occurred.
Palakkad District Collector K V Mohan Kumar said the unit had not renewed its licence after 2008. Though its owner had applied for renewal in 2008, it was rejected.
The workers were engaged in making crackers for temple festivals starting in the area from mid-February.
The state Government has ordered a police probe into the incident.