The explosion in a house in Khagragarh area killed suspected Jamaat militants Shakil Ahmed and Sobhan Mandal and injured Hasan Saheb.

Six people, two of them women, were arrested in the state by the West Bengal Criminal Investigation Department (CID), which was probing the case before the NIA took over.

Three key accused - Rajera Bibi alias Razia, wife of one of the dead militants, Amina Bibi, wife of the injured militant, and Hafez Mollah alias Badrul Alam Molla - were presented before the court, which remanded them in NIA custody till October 22.

Hasan Saheb, who is undergoing treatment at the state-run SSKM Hospital, and two others, who were subsequently arrested for selling SIM cards to the militants, will be presented before the court at a later date.

Following an application by the NIA on Saturday, a Burdwan court which was hearing the case transferred it to a court in Kolkata.

Meanwhile, an NIA team led by Inspector General SK Singh visited the blast site as well a madrasa in Simulia in Burdwan, where the accused were believed to have been radicalized.

The team on Sunday seized several objects, including Jihadi literature, chemicals and other incriminating items, from the madrasa.

Besides the arrest in West Bengal, six youths have been nabbed from Barpeta district in Assam for their alleged involvement in the case.

NIA teams are camping in Burdwan, Kolkata, Nadia and some parts of Assam in connection with the investigation.

A number of key players in the conspiracy have been identified and police as well as intelligence agencies have been alerted to look out for them.

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