Last month, during an exercise to test India's readiness for a militant attack, teams of coast guards approached Mumbai and surrounding areas by sea, just as assailants did before deadly strikes in 2008. Several teams slipped through undetected.

Officials say the response to the mock assault in the state of Maharashtra was not a disaster, but the shortcomings it exposed were a reminder of India's vulnerability to the kind of violence that hit Mumbai seven years ago, when 166 people were killed, and Paris only last month.

"There was a mixed result," said a navy spokesman in Mumbai, describing the mid-November exercise that, by coincidence, came days after gunmen targeted Paris on Nov. 13, killing 130.