NEW DELHI - Vistara, an Indian airline owned partially by Singapore Airlines, and AirAsia India have stuck to the rulebook and not rushed in to ban an Indian comedian, defying a public advisory to do so on Twitter from Indian Civil Aviation Minister Mr Hardeep Singh Puri.

Four major carriers - IndiGo, Air India, GoAir and SpiceJet - announced a ban on Mr Kunal Kamra last week after he accosted Mr Arnab Goswami, a controversial but popular Indian television news anchor sympathetic to Bharatiya Janata Party, on an IndiGo flight on the afternoon of Jan 28.

Mr Goswami's polemical shows are a primetime platform for launching invectives at critics of the government.

Mr Kamra, a known critic of the government, had posted a video the same afternoon on Twitter, where he is seen accosting Mr Goswami, asking him whether he is a "coward" or a "nationalist" as part of a nearly two-minute monologue.

Mr Goswami, who is the editor-in-chief of Republic TV, did not respond and kept his gaze fixed on his laptop with his earphones plugged in.

That same night, IndiGo tweeted that it had banned Mr Kamra from taking its flights for six months for what it described as "unacceptable behaviour".

The airline had tagged Mr Puri in its tweet. In less than an hour, Mr Puri had retweeted the post, saying: "Offensive behaviour designed to provoke & create disturbance inside an aircraft is absolutely unacceptable & endangers safety of air travellers."

He added: "We are left with no option but to advise other airlines to impose similar restrictions on the person concerned."

Within 24 hours, the three other airlines also announcedthey had banned Mr Kamra too, tagging Mr Puri in their tweets. This prompted criticism of the four airlines for kowtowing to the government and flouting established government procedures that determine who can be banned from flying and for how long.

Vistara and AirAsia India have not yet announced a similar ban on Mr Kamra. A statement issued to The Straits Times by Vistara said the airline will "review and follow due process in such cases". AirAsia India did not respond to a request for comment.

According to government rules, a "Level One" offence includes any unruly physical gesture or verbal harassment - including unruly behaviour from drunk passengers - for which the person can be banned from flying for up to three months.

IndiGo, on the other hand, banned Kamra for six months within hours of the incident. A six-month ban is reserved for "Level Two" offences of physically abusive behaviour on board an aircraft, which Mr Kamra did not indulge in.

Moreover, any decision to impose a ban requires the commanding pilot to file a complaint.

The pilot of the IndiGo flight Mr Kamra was on - Captain Rohit Mateti - did not do so and a public statement attributed to him said Mr Kamra had not defied instructions from the crew at any point and that his actions did not qualify as a "Level One" offence.

The airline concerned also needs to constitute an internal committee to adjudicate on a complaint against a passenger accused of being unruly and then arrive at a decision within 30 days of the complaint.

The passenger in question, meanwhile, is to be handed an interim ban of up to 30 days by the airline.

Other airlines may choose to deny service to the passenger only if the passenger is held guilty by the original airline's inquiry but are not compelled to do so. The passenger banned also has the right to appeal.

"It is clear that the whole action is high-handed," Mr D Sudhakara Reddy, the founder and national president of Air Passengers Association of India, told The Straits Times.

"It is a pity the passenger was not given an opportunity to be heard. They (the government and the four airlines) have not followed the rules laid down by themselves," he said.

The association has previously been part of internal committees set up by different airlines to adjudicate on complaints against passengers.

"We welcome the position that Vistara and AirAsia India have taken. They are not under any obligation to act on this matter," he added.

On Feb 2, Mr Kamra flew on a Vistara flight from Mumbai to New Delhi and tweeted a picture of himself in front of the check-in counter.

"My airport look all thanks to @airvistara following due process...#lovevistara," he said. Many others also posted messages online supporting the stand taken by AirAsia India and Vistara.

Mr Anurag Kashyap, a prominent Bollywood director, flew on a Vistara flight to Kolkata from Mumbai on Feb 3, choosing to arrive seven hours before he was required for an event in the city to avoid taking an IndiGo flight.

He told The Telegraph newspaper it was his way to oppose the "unreasonable" ban on Mr Kamra and added that he would not fly IndiGo until the comedian is allowed back on board.

On Feb 6, four individuals held up placards supporting Mr Kamra on an IndiGo flight from Varanasi to Delhi. The placards, posted by one of them on Twitter, read, "We condemn IndiGo's ban on Kunal Kamra #YouDivideWeMultiply".

Mr Kamra, meanwhile, has sent IndiGo a legal notice, demanding a public apology, 2.5 million rupees (S$48,470) for "causing mental pain and agony" and a revocation of the six-month ban.