Lucknow, Feb 27 (ANI): Three security guards were killed after some unknown miscreants opened fire on them and looted cash from HDFC bank's ATM booth in Hasanganj area of Lucknow. Reportedly, the incident took place when the custodians of the cash van were in the process of refilling money into an ATM of HDFC bank. Lucknow Inspector General Zaki Ahmed said that almost 50 lakhs has been looted and that investigation is going on in the matter. Police are trying to get the CCTV footages of the incident.