More than 20 pirates have been captured by the Indian Navy which has also rescued two dozen hostages from a hijacked Thai fishing trawler in the Indian Ocean.
It was the second such naval success in a week.
The operation began on Saturday evening when the Navy received information that a Greek merchant ship had been attacked by pirates by high-speed boats, although it had managed to avoid capture.
Two vessels from the Navy and Coastguard located the pirates' boats on Sunday morning and followed them back to a hijacked Thai fishing trawler, the Prantalay 11.
The Thai boat was apparently used as a mothership for launching raids on shipping.
After an exchange of fire, the pirates surrendered and were captured, along with the original crew of the Thai boat.
They are now being taken to Mumbai (Bombay).
The BBC reports the Prantalay 11 was one of three Thai vessels captured off the coast of Somalia last year. Another was sunk by the Indian navy in a similar operation last week.