New Delhi, Nov 11 (IANS): The civil aviation regulator on Thursday directed all domestic airlines to sell only "non-refundable" tickets which are bought using the old Rs 500 and Rs 1,000 notes at their airport counters.

According to industry sources, the instruction was issued by the Directorate General of Civil Aviation (DGCA) after a spike in business class ticket booking using old Rs 500 and Rs 1,000 notes was witnessed.

The new guidelines are seen as a step to curb any alleged misuse of the facility provided by the government to allow purchase of air tickets for immediate travel needs in the wake of currency demonetisation.

Following the new guideline various domestic airlines said that tickets bought with old Rs 500 and Rs 1,000 notes are strictly "non-refundable."

Full service carrier Vistara tweeted: "The tickets sold at airport ticket counters with Rs 500 and Rs 1,000 currency note are strictly non-refundable."

Budget passenger carrier AirAsia India said that it will accept the demonetised currency notes until 11:59 p.m. on November 11 at its counters across India to book flights.

"Guests who would like to make cash bookings can head to the airport counters from now until 11th of November. All flights booked using cash will be non-refundable," the airline said in a statement.

The clarity regarding the refund status came after a sudden spike was noticed in ticket bookings at airport counters.

"We had witnessed a four time increase in ticket booking at our airport counters during the last 48 hours," said Ajay Jasra, General Manager, Corporate Affairs, SpiceJet.

On November 8, Prime Minister Narendra Modi announced that hospitals, railway, bus and airlines ticket counters will continue to accept Rs 500 and Rs 1,000 old notes for the next 72 hours.

Modi announced these measures to smoothen the transition process of his major step for curbing the menace of black money in the country.

According to the Prime Minister, the people friendly measures will minimise the inconvenience of the government's decision to withdraw Rs 500 and Rs 1,000 denomination notes from Tuesday midnight.