The suspected militant injured in the Oct 2 explosion in West Bengal's Burdwan district was arrested by the CID Tuesday, taking the number of arrests to four.
Following improvement in his health, Hasan Saheb alias Sheikh Hakim, undergoing treatment at Burdwan Medical College and Hospital, was put under arrest and will be presented before a court once he is discharged, an officer said Tuesday.
Police earlier arrested three others including two women in connection with the blast that occurred in a house in Khagragarh area killing two suspected militants.
Besides the CID, a composite task force comprising officers from various state investigating agencies have been constituted to probe the incident for which the Mamata Banerjee led state government has been receiving flak from the opposition.
Both the Left Front and the Bharatiya Janata Party have alleged that people associated with the ruling Trinamool Congress are involved and also accused the police of destroying crucial evidences and covering up the probe.
The charges have been rubbished by the Trinamool as well as the state government.