Minister of Civil Aviation Hardeep Singh Puri on Wednesday said that domestic flights will begin to operate in a “calibrated manner” from May 25, even as India struggles to contain the coronavirus pandemic.

“All airports and air carriers are being informed to be ready for operations from May 25,” he tweeted.

Puri also said that the Ministry of Civil Aviation will separately issue Standard Operating Protocols for passengers travelling by air. Flights, both domestic and international, had been suspended in March, as India entered a lockdown to combat the spread of Covid-19. The fourth phase of the lockdown will end on May 31.

Asked whether the middle seat in these flights would be kept vacant, Puri answered in the negative. “It’s not viable to keep the middle seat vacant,” he told ANI. “Even if you keep middle seat vacant you’ll still have a situation where the prescribed distance for social distancing isn’t followed. If you were to do it then you’ve to hike up airline ticket price by 33%.”

Puri told the news agency that while only a few flights will start on May 25, the Ministry of Civil Aviation will try to increase their number based on “experience”.

“We are commencing operation of flights in all parts of the country, including Kolkata,” Puri said, referring to the flooding caused by Cyclone Amphan in the West Bengal capital. “But the weather and climatic conditions in Kolkata may not permit flight services at present.”

On Tuesday, Puri had said that domestic flights to different cities in India will resume once the state governments express their willingness to allow operations “in the spirit of cooperative federalism”. His comments came after the Centre said the consent of home states of migrants would no longer be required for the special trains transporting them.

On May 9, Puri had said that preparations to restart civil aviation operations are in place. “As soon as a decision is taken in this regard we will be able to take off immediately,” he said. “We also foresee changes in the way people travelled thus far. A calibrated reopening can happen after the lockdown.”

India has so far recorded 1,06,759 coronavirus cases with 3,303 deaths, according to the Union Ministry of Health and Family Welfare.