After interrogating the two women arrested on Sunday, in connection with the Burdwan blast, the West Bengal police revealed that they were members of a Bangladeshi terror group and had links with al-Qaeda.
The five people involved in the blast were reportedly members of the Islamist group, Jamaat-ul-Mujahideen Bangladesh (JMB), which is said to have links with the banned fundamentalist outfit, Jamaat-e-Islami, Hindustan Times reported.
These include the two arrested women, Amina Bibi and Rajira Bibi, along with the two men killed in Thursday's bomb blast in their own house, Shakil Ahmed and Sovan Mandal and another injured man, Hasan Saheb.
The police had collected evidence including pamphlets that clearly indicated their links with al-Qaeda, which had earlier released a video, in which the organisation's leader announced that they would establish their branch in India as well.
"In the pamphlets, we found words and phrases like 'mujahid' and 'salaam to our brothers in Chechnya'. We also found the name of Zawahiri (the Qaida leader) in some pamphlets," The Telegraph quoted a police officer as saying.
They had reached Burdwan three months back, and since then they have been manufacturing bombs and channelling it through their members to Bangladesh where they had plotted a terror attack, according to reports. In the last three months, they had parcelled four consignments containing bombs to Bangladesh through couriers.
While HT reported one of the women saying that the bombs that they were making in that house were not meant for any terror attacks in India, a Times Now report said they had plans to attack West Bengal during its major festival, Durga Puja.
"One agenda of the terror group was to attack West Bengal during festivities while the other plan was to smuggle bombs across the border to target Bangladeshi establishment," Times Now reported.
The National Investigation Agency, Special Task Force, the Anti-Terrorism Squad and the Criminal Investigation Department were handed over the investigation after the two women were arrested in connection with the explosion in a house in Burdwan's Khagragarh area.