Five people have been arrested by detectives in connection with the killing of Saiham Group assistant general manager Monirul Islam from Khilgaon area in the city on Monday night.Identity of the arrestees could not be known immediately.Deputy Commissioner of the Detective Branch (East) of Dhaka Metropolitan Police (DMP) Mahbub said tipped off, a team of DB police conducted a drive in the area and arrested the five at night.Monirul Islam, 35, AGM of Saiham Group, who went missing on May 17, was found dead at Shekher Jaiga in the city’s Khilgaon area on May 18.