Police in a drive detained Shafiul Alam, the prime accused in the murder of two minor siblings at Dhulipara village in Sadar South upazila of Comilla district on Monday night.Additional Superintendent of Police MD Ali Ashraf Bhuiyan of Comilla on Tuesday morning said police arrested Chhotan from the area around 10pm by tracking his mobile phone.In a primary interrogation, he confessed to the murder, added the SP.On February 27, police recovered the bodies of Joy, 7, and his younger brother Moni, 5, sons of Abul Kalam, from their house at Dhulipara.Alam allegedly strangulated the two children, who are his stepbrothers, to death.