The ban on flights to Calcutta from six cities with high Covid prevalence, including Delhi and Mumbai, will be extended till August 31, officials said.

The ban was to expire on August 15.

“I am further directed to inform you that the suspension of flights from the aforesaid cities to Kolkata will continue till 31 August, 2020,” reads a letter from Bengal’s home secretary Alapan Bandyopadhyay to civil aviation secretary P.S. Kharola.

“We’ll announce the extension of the ban in a day or two,” said an official of the Calcutta airport.

The ban on flights to Calcutta from Delhi, Mumbai, Chennai, Pune, Nagpur and Ahmedabad, which have been reporting a large number of Covid-19 cases every day, kicked in on July 6 following a request from the Bengal government. The ban was till July 19 but was extended till July 31 and then till August 15.

Airlines had opened bookings for flights between Calcutta and these cities post-August 15 but tour operators said they were not taking any bookings.

“Every time passengers have to cancel or rebook. We will book tickets to these six cities only after the state government formally announces resumption of operations. Till then we are booking passengers to these places through other cities,” said Anil Punjabi, chairman, east, Travel Agents Federation of India.

An airport official said airlines were suffering heavy losses because of the ban. “The flights to Delhi, Mumbai and Chennai carry at least 25 per cent more passengers compared with flights to other cities,” he said.