Commissioner of Dhaka Metropolitan Police (DMP) Md. Assaduzzaman Mia on Monday said not as DMP Commissioner but as a police member I want to assure that the blood of Assistant Commissioner Robiul Islam and Gulshan Police Station’s officer-in charge Salauddin, would not go to vain.The Commissioner swore this in mourning program of Assistant Commissioner Robiul Islam and Gulshan Police Station’s officer-in charge Salauddin, who were killed in Gulshan Holey Artisan Bakery attack as they were tried to catch out the attacker in first stage of attack, at Razarbagh Police Line in the city.He said we will find out who will killers and how they going missing.He claimed that the Iman of the police is very strong and they will face every challenge with courage’s.Police officials were present at the mourning program.Earlier, gunmen seized Holey Artisan cafe at 8.45pm, killing 20 hostages and two officers in a siege that ended Saturday morning.All the hostages killed were foreigners and six gunmen were killed while one was held alive the military said. Troops rescued 14 hostages, according to Brig. Gen. Mujibur Rahman of the Bangladesh army.The country’s worst hostage crisis ended on Saturday morning when heavily-armed commandos stormed the popular Dhaka eatery in the diplomatic enclave and killed militants who had been holding many people, including foreigners, captive for over 12 hours.