Members of Rapid Action Battalion (RAB) arrested six members of banned militant outfit Ansar Al Islam from Narayanganj's Rupganj on Sunday . The arrestees are Abdur Razzak alias Ishak alias Saiba, 41, Shariful Islam alias Murad, 31, Rahman alias Usaiman, 27, Muhammad Zakaria alias Abar, 24, Al Amin alias Robin alias