"A seal from a factory in Bihar was found on the three AK22 rifles recovered after the Gulshan terror attack," Counter-Terrorism and Transnational Crime chief Monirul Islam was quoted as saying by the Dhaka Tribune.
The terrorist was killed during a raid on a house in Dhaka's Rupnagar area and was identified by police as top Neo-Jama'atul Mujahideen Bangladesh leader Chowdhury's 'second-in-command'.
Canadian-Bangladeshi Tamim Ahmed Chowdhury and his two associates were killed during an encounter at the militants' hideout.
Neo-Jamaat-ul-Mujahideen's wanted leader Nurul Islam alias Marjan and another unidentified extremist were killed by Counter-Terrorism and Transnational Crime unit in Mohammadpur Beribadh area of the capital.
13 of the 17 militants who were presumed to have plotted the attack were killed in encounters so far, said police.