The militants were gathering money and materials for their outfit Jama'atul Ansar Fil Hindal Sharqiya and had gone into hiding due to recent raids by law enforcement
Afroza Begum, 65, and her house help 'Bithi' were found dead with their throats slashed in a flat on Dhanmondi road No. 28 on Nov 1.
Her daughter Advocate Dilruba Sultana Ruba started the case against an unidentified woman, said Dhanmondi Police Station OC Abdul Latif.
But the law enforcement agency is yet track down the unidentified woman, said OC Latif. Detective police are also running a shadow investigation into the murder.