Kannur: Seven persons were injured when steel bombs, being manufactured illegally in an unoccupied house, exploded at Parad near Panur in Kannur, police said.
The steel bombs went off last night, they said, adding that 10 similar bombs were recovered from the house.
The injured have been taken to the Kozhikode Medical College and four of them are said to be critical.
The police have begun investigation into the incident.