Photos of a few business class passengers bitten by bed bugs were widely shared online in the past week.

Air India has since apologised and ordered an inquiry. It also promised to "rigorously fumigate" the plane.

India's biggest international carrier, the airline is in severe debt.

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Adding to its woes, the company has lost market share to new entrants and suffers a bad reputation of having poor service and cancelling flights.

A few years ago, an Air India plane travelling from Mumbai to London was forced to turn back mid-flight after a rat was spotted on board.

Air India: The airline everyone loves to hate

Ayeshea Perera, BBC News Delhi

Air India is often in the news for all the wrong reasons. From rats on flights to clogged toilets to inefficient flight crews, the constantly negative headlines have often led to newspapers declaring the airline a "national shame".

However the truth is slightly more nuanced than that. Of course Air India has had a completely avoidable series of mishaps that have been embarrassing to say the least. However it also boasts one of the most modern fleets in the world, some of the best pilots in the industry, and there have certainly never been any incidents that involve crew members seriously injuring passengers.

In India the overwhelming feeling towards the airline is one of weary affection. Incidents like this are often treated as par for the course, and do not generate scandal in the way you would expect. Besides, that is, one recent incident that had everyone up in arms - the decision to only serve vegetarian food on domestic flights.

Air India apologised one week after passengers who had flown from New York to Mumbai on 17 July complained of being bitten by bed bugs.

Some shared photos in which their arms appeared to be covered in bug bites. Others shared close-up images of their seats, alleging they were infested with bed bugs.

One of India's oldest airlines, Air India has not turned a profit since 2007.

In June 2017, India's cabinet approved plans to privatise the carrier. But it failed to attract buyers after the federal government offered to sell a controlling stake.

Any buyer would have to take on about $5bn (£3.6bn) of debt, which is only about half of what the airline owes.