India's aviation regulator has told airlines not to take bookings as the government has not yet decided when to recommence flights after a lockdown scheduled to end on May 3.
The Directorate General of Civil Aviation (DGCA) issued the notification after some Indian airlines started taking bookings for May 4 onwards.
Indigo, the country's largest airline, and Vistara, owned by Singapore Airlines and Tata Group, had said earlier they would begin operations in a phased manner from May 4.
Prime Minister Narendra Modi extended the lockdown across India to May 3, from April 14, as the number of coronavirus cases spiked, but permitted some sectors to partially open up after April 20.
"All airlines are hereby directed to refrain from booking tickets ... they shall be given sufficient notice and time for restarting operations," the DGCA notice said.
India has recorded 16,116 cases of the coronavirus, with 519 deaths.
Indian budget airline GoAir has asked as many as 90% of its 5,500 employees to go on indefinite leave without pay as the Indian government's coronavirus flight restrictions dry up cash flow, Bloomberg News reported on Sunday.
The airline will keep paying a small number of employees on payroll to restart operations when the government allows flights, the report said, citing people with knowledge of the matter.
India's civil aviation minister Hardeep Singh Puri said in a tweet late on Saturday that the government is yet to take a decision on domestic and international flights.
Puri said "airlines are advised to open their bookings only after a decision in this regard has been taken by the Government."
Indian Prime Minister Narendra Modi announced a 21-day national lockdown in late March to contain the spread of the virus outbreak. The lockdown has been extended until May 3 at least.
GoAir is checking with the government if the airline can continue sale of tickets for travel after the national lockdown ends on May 3, the report added.