Improvised explosive devices and the material to make them - watch dials and detonators - and SIM cards were recovered from the house, located in Khagragarh area. Some printed material was also found, which had references to Al Qaeda chief Ayman Al Zawahri, Indian Mujahideen and even the Chechen rebels.
Police suspect the group was involved with a terrorist outfit and they were using the rented house as a shelter.
The National Investigation Agency and the Intelligence Bureau are already probing the possible involvement of terror groups like Lashkar-e-Taiba and Harkat-ul-Jihad-al-Islami. The Special Task Force, the Anti-Terrorism Squad and the Criminal Investigation Department are involved in the probe as well. The agencies have been on their toes following a recent Al Qaeda announcement regarding the setting-up of a module in the Indian subcontinent. (Read: Al Qaeda's India Branch and the Man Who Will Head it)
The arrested women were identified as Rejara Biwi and Amina Biwi. Rejara Biwi's husband Shakil Ahmed was one of the men who died in the blast. Amina Biwi's husband Abdul Hasan was injured. The second person killed in the blast has been identified as Shobhan Mondal. The owner of the house, Hasan Chowdhury, is being questioned.
"Following their interrogation, we have found sufficient evidence to suggest that they are a part of the conspiracy," Assistant Superintendent of Police (Burdwan) Tarun Halder told the news agency Indo-Asian Abroad News Service. The suspected militants had rented the house a few months ago, the police said.
The opposition BJP has accused the Mamata Banerjee government of turning the state into a terrorist haven.
Alleging that a Trinamool Congress office was located on the ground floor of the house, state BJP leader Siddharth Nath Singh accused the Burdwan police of destroying evidence in the case.
"Why was the National Investigation Agency informed almost a day late? We can safely conclude that West Bengal under Mamata Banerjee's rule has become a safe haven for anti-national elements and jihadi activists," he said.
Addressing a press conference in the evening, TMC general secretary Mukul Roy said the BJP and the CPI(M) were merely trying to "disturb the peace and harmony in Bengal". "Mamata Banerjee has never allowed any communal tension in Bengal. Till her last breath, she never will," he said.