Travel to Hong Kong has been the worst affected, with no bookings coming in for the forthcoming holiday season.

As a result, Air-India has cancelled all flights to Singapore and Kuala Lumpur from Delhi, and is planning to cancel flights to Hong Kong. Flights to Singapore from Mumbai will be rescheduled.

"The passenger load factor for flights to Hong Kong has dropped to below 50 per cent and a further dip is expected. We may, therefore, have to call off another flight on the Delhi-Hong Kong sector," the executive said.

The airline has already suspended two of the five flights it operates in this sector. Though other Southeast Asian airlines like Cathay Pacific, Singapore Airlines and Thai Airways had not yet suspended their operations to India from the Sars-hit regions, travel agents said if the situation did not improve, there could be a spate of cancellations.

"Hong Kong has not seen any booking for May and June till now. There was a 75-80 per cent decline in bookings for Hong Kong in April," said Vikas Khanduri, regional manager (north India), Cox & Kings.

Business travel, which depends on Hong Kong and Singapore as the two most popular destinations, has been the worst hit.

Meanwhile, airport authorities have instituted more rigorous screening for passengers coming into the country. "We have set up six help-desks, which are manned by doctors and other medical personnel round the clock," said P S Nair, airport director, Indira Gandhi International airport.

An isolation-cum-examination room has also been set up at the airport to quarantine suspected patients till they are  transferred to a hospital.

The Delhi airport had its brush with the dreaded disease last week when a tourist from New Zealand, flying in from Bangkok, was detected with Sars-like symptoms. He was shifted to the Ram Manohar Lohia Hospital.

Health authorities at the Delhi airport also conducted a four-day training session for various airline staff. Passengers are also being asked to fill up health-related forms before disembarking.