Anti Terrorism Unit (ATU) yesterday arrested an alleged member of banned militant group Ansar al Islam from Rupganj upazila in Narayanganj district. On secret information, a team of ATU arrested Sabuj Sheikh, 26, and seized a mobile from Sultanbag area around 12:30pm, says a press release. He used to operate a Facebook ID called "Sotter Shondhane" to propagate extremism. He