With the arrest of two persons, Madurai City Commissioner of Police T. Senthil Kumar said that the case of hurling petrol bomb at a house in Anupanadi on Saturday was cracked.
Hussain, who is an accused in three cases and Samsudeen, accused in five cases, have been arrested with the help of technical investigation like closed circuit television camera video footage and using mobile phone signals.
"The investigation has revealed that two more are involved in throwing bombs at the house of an RSS functionary, M.H. Krishnan," he said.
The City police have formed six teams to nab the other accused.
The Commissioner said that the motive for the bomb attack was yet to be established.
Meanwhile, the police have arrested one Sheik Alaudeen of Melur on charges of assaulting a police constable, Duraimurugan, on September 22 at Goripalayam.
The Commissioner said that the constable, attached to Organised Crime Intelligence Unit, was on duty in the locality when National Investigation Agency was conducting raids at the houses of Popular Front of India functionaries.
Tallakulam police had registered a case.
In a related development, the city police have booked a petrol bunk operator in Teppakulam for violating the police advisory against "loose" selling of petrol in bottles, he added.
Deputy Commissioners of Police R. Srinivasa Perumal, and Mohanraj were present.