International flight operations may start by mid-June or end-July if the COVID-19 virus "behaves in a predictable manner", Civil Aviation Minister Hardeep Singh Puri said Saturday afternoon, during an online discussion with the public to clarify norms governing "calibrated" restart of domestic flights from Monday.

Mr Puri said the government was working towards restarting a "good percentage" of passenger flights  that have been grounded since the start of the lockdown to break the coronavirus chain of transmission.

"Why wait till August or September? If situation eases or improves, if virus behaves in predictable manner and we get used to co-exist(ing) with it, we're in position to make arrangements. Why not start by June middle or end July?" Mr Puri said today.

During his interaction the minister also said he did not understand the need to quarantine domestic fliers who show "green" status on the Aarogya Setu app. He made a similar point during a press briefing on Thursday, during which he revealed details of revised flight ops, including air fares.

Mr Puri's comment was followed by as many as six states, including Kerala, Karnataka and Assam, insisting that people arriving via domestic flights will be quarantined.

This morning Karnataka said incoming passengers from six states with the most infections will have to undergo seven-day institutional quarantine and seven days of home isolation. Exemptions will be made for the elderly, the terminally-ill, children and pregnant women.

On Friday, Tamil Nadu urged the centre to rethink the reopening of air travel, citing a surge in coronavirus cases in state capital Chennai and non-functioning public transport, which will trouble passengers commuting between the airport and the city - a distance of around 10 kilometres.

Chennai airport has been closed for passenger traffic, as have all others in the country, since the COVID-19 lockdown began (File)

The debate over quarantine being mandatory for air passengers was kicked off by Mr Puri on Thursday, when said an unnecessary "fuss" was being made over quarantine of domestic air travellers.

He pointed out that as per revised SOPs governing air travel during the lockdown, those showing "red" on the Aarogya Setu app, which he promoted as an "excellent contact-tracing device", would not even be allowed to enter the airport, let alone board a plane.

"I don't know why we are making such a fuss on the quarantine issue. Bhai, this is domestic travel. Same laws will apply here that applies when you travel by train or a bus... People who are positive will not be allowed to board the flights," he said.

Passenger flight operations were stopped in March after a nationwide lockdown was ordered to halt the spread of the COVID-19 virus; cargo flights, those for medical evacuation and special flights to repatriate Indians stranded abroad were allowed to operate.

On Wednesday Mr Puri said domestic passenger flights would be re-started in a "calibrated" manner.

The resumption comes as the country experiences a worrying surge in fresh COVID-19 cases - nearly 25,000 have been recorded over the past four days, with 6,654 reported over the past 24 hours, according to government data this morning.

The total number of cases in India has crossed 1.25 lakh, with 3,720 deaths reported.

The Railways has already moved to gradually restart services; it has been running trains for migrants since May 1, as well as 15 special passenger trains starting from New Delhi.

Starting June 1, 200 regular passenger trains will also begin operating. Passengers will also have to show "green" on the Aarogya Setu app before travelling, and will have to spend 14 days in isolation on arrival.