Thousands of airport staff began an indefinite strike at 127 airports across India on Wednesday, but flights from India's main cities of Mumbai and New Delhi were unaffected, according to airport officials.
About 14,000 union members are striking over the imminent closure of two airports in Hyderabad and Bangalore, both home to many of India's software and outsourcing companies, to make way for new facilities.
Strikers are mostly employed in airport support services, and include electricians, plumbers, cleaners, engineers and emergency fire support staff.
"The flights are all on schedule in big cities like Delhi and we are not facing any problems so far," Arun Arora, Airports Authority of India spokesman said in New Delhi.
But in Kolkata, capital of communist-ruled West Bengal state, hundreds of employees did not turn up for work, officials said.
In Kolkata, as well as Hyderabad, where authorities plan to shut down the old airport, several aged passengers were seen carrying their own baggage as there was no one to help them, officials and witnesses said.
"I cancelled my planned business trip to Jaipur because of the strike today. I hope everything gets resolved very soon," Ashok Parmar, 40, said by telephone from Kolkata.
Hundreds of air force personnel in most cities were asked to be ready to take charge if the strike drags on, officials said.
New airports with better facilities built by private developers are due to open soon in Hyderabad and Bangalore.
The union says that when that happens, staff at the old airports will lose their jobs or get shifted elsewhere.
Authorities have said that no staff would lose their jobs as they will be needed at other airports.
"These are all lies and the government must not shut down the old airports," MK Ghoshal, the leader of the striking union, said.