The Indian navy has arrested 16 Somali pirates and freed the same number of crewmen after a battle with a hijacked ship in the Arabian Sea, a spokesman said on Monday.
A navy vessel and a coast guard patrol boat on Saturday intercepted an Iranian fishing boat that had been seized by pirates near the Lakshadweep islands off India's west coast.
The pirates were attempting to capture another merchant ship, the MV Maersk Kensington.
The navy vessel ordered the hijacked ship to halt but the pirates opened fire, a government statement said.
Attacks by pirates off the Indian coast have become increasingly violent.
The Indian navy said that before Saturday's arrests 104 pirates had been apprehended in three similar incidents since January 28.
Last month, India warned of an increased threat to shipping off its southwest coast, as Somali pirates hunt targets beyond African waters to evade the clutches of an international naval force.
The Indian government says it is working on a law to tackle piracy and find ways to negotiate with pirates for the release of Indian sailors.
The international community is facing difficulties in prosecuting the growing number of pirates off Somalia, a lawless, war-torn country that sits alongside one of the world's most important shipping routes.