A scare was triggered at the Indira Gandhi International airport in the wee hours on Friday after a sound similar to gunshots were reportedly heard from the facility. The control room of the CISF received a call at around 1.10 am from passengers that they heard sound of gunshots from one of the gates of international departure lounge of the airport, official said. "We received a call that some passengers heard a sound similar to two gunshots, but there were no eyewitnesses. No evidence has so far come up to suggest that it was a firing and we cannot confirm it as a gunshot," Udayan Banerjee, DIG, CISF and incharge of security at Delhi airport told PTI."After the sound, the CISF and Delhi Police deployment swung into action and intensified the checking at the airport," he said adding the passenger movement is normal and arrival and departure is also functioning smoothly. Delhi police spokesperson Rajan Bhagat said, "a call was received that three to four rounds of firing has taken place at the airport but no one was injured." "We are not yet sure whether any firing actually took place. We are verifying the facts," Bhagat added. CISF officials said all preventive measures have been taken and a security drill has been put in place. Banerjee later told that vehicle movement to and from the airport was restricted following a sound similar to gunshots were heard by the security personnel. He said, while the checking was going on, a white colour Qualis car jumped the queue and sped away. When asked whether the number plate was noticed, he said, "We are not really sure about the number plate but I was told it was an HR (Haryana) registration vehicle." Senior CISF personnel have also arrived at the scene, he said. Reports suggested that it could also have been a mock drill, but senior officials of the CISF, however, denied so.