A strike at India's state-run domestic airline has entered its second day, stranding thousands of passengers.
The merger is the latest shake-up in the Indian aviation sector
The number of cancelled flights increased as some cabin crew joined 12,000 ground staff in the stoppage, an Indian Airlines spokesperson said.
Baggage handlers, check-in staff and other airline employees are demanding better wages and career prospects.
They are angry at a government plan to merge the struggling airline with the country's flagship carrier, Air India.
The two have faced increased competition from new private airlines in recent years, and Indian Airlines has seen its market share drop to 20%.
Although the airline has promised there will be no retrenchment, staff fear that the merger with Air India may eventually lead to job cuts or hurt their future prospects.
The strike began on Tuesday night after a breakdown in talks with management.
Chaos prevails at some of India's major airports, including the capital, Delhi, the financial capital, Mumbai (Bombay), and the IT hub of Bangalore.
"As of now we have cancelled 10 flights from Mumbai to various places," Indian Airlines spokesperson in Mumbai, K Bharati, told the BBC.
It has been a frustrating time for passengers across the country
"We may have to cancel more flights during the course of the day. We are trying to inform all our passengers in every possible way," she said.
Ms Bharati said the number of cancellations has increased on Thursday as some cabin crew, who are members of the protesting union, have also joined the strike.
A spokesperson for Mumbai International Airport Private Limited, Manish Kalghatgi said: "Some of our staff helped out Indian Airlines with baggage handling when the strike started but the unions opposed it and so we had to pull them out. Now, as and when there is a need our people go to assist them."
Mr Kalghatgi said the situation at the airport was still "quite bad" and that the Indian Airlines schedule had been disrupted.
Although flights operated by private airlines were mostly on schedule, long queues of prospective travellers have been reported.
Some passengers say there has been little information on when services will return to normal, or what to do until they do.
Indian Airlines operates more than 300 flights a day, carrying some 30,000 passengers.
On Wednesday the Delhi High Court declared the strike illegal and ordered the 12,000 employees to resume work.
The government has suspended 23 strikers and is threatening action against others.
Civil Aviation Minister Praful Patel said the strike was not in the interests of staff or the airline and employees should understand that in times of competition, passengers have other options.
The striking workers have refused to call off their strike, although they say they are "open to talks".
The merger of Indian Airlines with state-owned international carrier Air India is aimed at making them able to compete more effectively with private carriers.
Set up in 1932, Air India is the country's flagship international airline, serving more than 40 destinations worldwide.
Indian Airlines is focused on the domestic market, but recently began some flights to destinations in Asia and the Middle East.
In the last few years, privately owned rivals such as Jet Airways and Kingfisher Airlines have taken market share from the duo.