Earlier this week, officials received warnings that militants could attempt to hijack passenger planes to coincide with Saturday's anniversary of the destruction of the Babri mosque in northern India by Hindu extremists in 1992.

New in-depth checks have been introduced on top of existing measures to 'ensure no security problems arise,' a senior police officer at New Delhi International Airport said on condition of anonymity.

One woman travelling through the airport told NDTV television: 'I'm happy if they do 100 checks as long as passengers reach their destinations safely.

I'm ready to go through any amount of checks.'

All major airports - including those in Bangalore, Chennai, Hyderabad, Kolkata, Mumbai and New Delhi - had already been on high alert following a warning that armed gunmen could storm airports and take hostages.

The stepped-up airport security came in response to 'fresh intelligence inputs' about the hijack warnings, said Moushmi Chakravarty, spokeswoman for India's civil aviation ministry.

Security was initially increased after the Mumbai attacks last week in which 10 militants targetted multiple locations in India's western financial capital, killing 163 people including 26 foreigners. Nine militants were killed.

Security is traditionally tight across India on the anniversary of the demolition of the Babri mosque.

Hindu zealots tore down the 16th-century structure in the town of Ayodhya in Uttar Pradesh state, igniting deadly Hindu-Muslim riots across the country. -- AFP