The three burqa-clad persons entered from the emergency gate of the Medicity Medanta hospital at 2.50 am and sat close to the cash counter for sometime, Hawa Singh, PRO, Gurgaon said.
They could not succeed in their attempts as a woman security guard intercepted them and enquired their suspicious activities, following which one of them took out a pistol and threatened her of dire consequences if she raised an alarm, Singh said.
An FIR has been registered and the CCTV footage is being examined, Singh said.
Efforts are being made to identify the three persons, he added.