The building in Burdwan where an explosion occurred on October 2
The blast in West Bengal's Burdwan district has raised a question in intelligence circles. Is there a joint venture between Bangladeshi and Indian terror outfits?
Most experts say the answer is a resounding yes. If the external outfit is the Jamaat-e-Mujahideen Bangladesh (JMB), what are some of the Indian groups linked to it, groups which have helped JMB set up its network and bomb-making units in Bengal?
Shakil Ahmed aka Shakil Gazi, the man who died in the Burdwan blast on October 2, is believed to be a Bangladeshi. Before setting up the bomb-making unit in Burdwan, he used to live in Murshidabad district's Beldanga with his wife and child, where he ran a burqa-making factory.
Interrogation of his widow, who was arrested from the blast site, and intelligence inputs suggest he was a member of the JMB which entered into a joint venture with Indian terror groups to set up shop in Bengal.
"This was definitely a joint venture between at least two groups of terrorists, if not three," says Subir Bhaumik, a journalist who has been a long-time Bangladesh watcher. "The JMB was definitely involved, from all evidence, This was actually something that was happening over a period of time."
Manash Ghosh of the Statesman newspaper agreed as well.
"No doubt about it. It is absolutely sure. I hope our investigating agencies are able to unearth the nexus. On the ground, we can see it happening," said Mr Ghosh.
Names of many Indian terror groups have surfaced in connection with the blasts, including the Indian Mujahideen, Al Jihad, Al Ummah and even SIMI.
But why would JMB want to make bombs in Bengal for export to Bangladesh?
Dhaka watchers suggest that Shiekh Hasina made it impossible for the JMB to function in Bangladesh after is ban in 2005.
"It was getting too hot for Jamaat to operate in Bangladesh," said Mr Ghosh. "Many of their cadres were getting killed in crossfire, in encounters with rapid action battalions of Sheikh Hasina government."
A probe by the National Investigation Agency is currently underway into the October 2 blast.