According to police here, Pachayappan, the Jipmer employee, and Anandan of Ouppalam had previous enmity.
Anandan was absconding for some time following police registering a case against him.
Meanwhile, Deisingh, son of Pachayappan and two of his friends went to a tea stall this morning where the gang attempted to attack him.
Deisingh ran home and locked himself up. The irate gang, which followed him, hurled the bombs at his house damaging the front portion and two motorcycles parked there.
His friends, who sustained injuries, were treated in a private hospital.