New Delhi, Oct. 24: The Union civil aviation ministry, alarmed by a 75 per cent rise in the number of people slipping into airports with fake online flight tickets, has asked airlines and airport operators to tighten entry checks.

The ministry has, until September 30 this year, documented 69 instances from seven major airports of people using fake e-tickets to enter security zones - mainly the area around check-in counters - compared to about 40 cases last year. Such violations are viewed as a major security breach.

Delhi's Indira Gandhi International Airport accounted for the maximum number of cases (27), followed by Mumbai (15) and Calcutta (11). Airports in Chennai, Hyderabad, Patna and Bangalore also detected similar unauthorised entries. Four of these airports are privately operated.

"We have instructed airlines to introduce additional security features on every e-ticket they issue," an aviation ministry official told this newspaper.

"Airport operators - the Airport Authority of India and private operators - have also been directed to provide special scanners to security agencies that can distinguish genuine bar codes on tickets from fake ones while checking passengers at the entrance," the official added.

At present, e-tickets issued by airlines only have passenger details and the date of travel, apart from a unique passenger name record.

Another government official said in most cases, people who had used fake e-tickets to enter airports had come to see off family members or friends and had "luckily not posed any major security risk". Some had come to only see the airport and loiter around, the official said.

In most cases, the defaulters - if caught - were let off after interrogation and brief detention.

"But this is a grave concern and highlights a major loophole in our airport security system. Although, as of now, we have not given a timeline to airlines or airport operators to introduce a new system of checks, we will do it soon in a follow-up meeting," he said.

A senior executive with the Federation of Indian Airlines - a body that represents some major private airlines - said air carriers would whole-heartedly support the introduction of secure flight e-tickets. But it will take time to make such changes as over half the e-tickets are sold through travel agents.

"This makes it difficult as changes have to be made at the agent level, which will require software changes and other upgrades," he said. "We cannot have a system where airlines offer secure tickets and the ones issued by travel agents do not have those security features."

Sources in the Bureau of Civil Aviation Security, which is responsible for maintaining security at airports, said it was coming up with foolproof guidelines to tackle the problem.

"We will guide airlines and airport operators on how unauthorised entry into airports can be totally prevented. We are also studying practices in use in western countries," a bureau director said.

Aviation safety experts said the issue was of paramount importance at a time when the country was under constant threat of terrorism.

"The revelations are shocking and should be treated with utmost urgency. An unauthorised and illegal entry in the security hold area of an airport cannot be taken so lightly," said Gaurav Bhasin, a Mumbai-based air safety consultant.

"Indian airports cater to high passenger loads and there is a need for stricter norms to be adopted," said Bhasin who has worked as a safety expert with several airlines. "I am surprised that despite such high numbers of cases emerging, security agencies are still considering a proper mechanism to handle the issue."

About 90 million passengers annually travel by air in India, the world's ninth-largest aviation market. A report by the International Association of Air Transport - a body of over 200 air carriers globally - said India was poised to be the third-largest growing market by 2020, after the US and China.