NEW DELHI: 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. ( Watch )

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 said.

"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.

Airports across the country were on Thursday put on high alert in the wake of intelligence reports that terrorists from Pakistan or Afghanistan may strike using a hijacked aircraft even as the Indian Air Force said it was ready to counter a 9/11-type aerial attack on New York.

Additional contingents of CISF and police inside and outside the Delhi airport has already been deployed, authorities said.