Police on Thursday night detained four members of Harkat-ul-Jihad-al Islami Bangladesh, a banned outfit with two knives, one machete, four cocktails, electronic device, 14 petrol bomb and some jihadi books from Nanduyain area in Joydebpur of Gazipur.Gazipur’s superintendent of police, Md Harun-ur-Rashid, said in a press briefing.The four include two engineers, an Arakan returned militant and a worker.The arrestees were plotting bomb attacks at Nanduain area in Joydebpur , he added.