A secret chamber was found on Sunday by sleuths of the NIA at the residence of suspected al-Qaeda terrorist Abu Sufiyan, one of the six arrested from Murshidabad district in West Bengal, officials said. The chamber, measuring 10x7 feet, was found during a raid at the house in the Raninagar area of the district, a senior district police officer said.

Several electronic gadgets and a board of bulb were also found during the hour-long raid at the single-storied house, he said. Sufiyan's wife later told reporters that the chamber was dug for a septic tank for an attached toilet.