Piles of rubbish littered airports in India and toilets lay dirty as a nation-wide strike by airport workers affected most of the 127 centres around the country for a second day on Thursday.
But flight schedules were mostly unaffected and contingency measures were in place, Arun Arora, a spokesman for India's airports said in New Delhi.
About 14,000 union members are striking over the imminent closure of two airports in Hyderabad and Bangalore, both home to many software and outsourcing companies.
Civil Aviation Minister Praful Patel said late on Wednesday that the two old, state-run airports would be shut down, despite protests, to make way for new modern facilities run by private firms.
Strikers are mostly employed in the support services, and include electricians, plumbers, cleaners, engineers and emergency fire support staff.
In Kolkata, capital of communist-ruled West Bengal state, striking employees held rallies and shouted slogans outside the international terminal, officials said.
"The strike will gather momentum as more and more employees join us now," said Aparesh Das, a union leader.
At least 479 air force personnel were deployed in 21 major airports in the country to help flight operations, an air force spokesman said.
Although authorities say there will not be any job cuts when the new airports open, the union disagrees.
The union members fear once private operators take over operations, staff at the old airports could lose their jobs or could be forced to shift base.
Travel agents said they were worried that foreign tourists could cancel trips to India for a while.
"We are getting calls from tourists all over the world. They are worried about facilities in airports, especially toilets and baggage handling," Anil Punjabi of the Travel Agents Federation of India said from Kolkata.