The Indian navy captured 23 pirates who threatened a merchant vessel yesterday in the Gulf of Aden, where dozens of ships have come under attack by gunmen in recent months.

Indian navy ship, INS Mysore, was escorting merchant ships in the region near Somalia when it received a distress call from seamen on board the MV Gibe, who said they were being attacked by two boats.

The call said the pirates were firing as their boats closed in on the Gibe, the Indian government said.

The boats attempted to escape when they saw the Mysore and its helicopter, but were boarded by Indian marine commandoes.

The pirates had a substantial cache of arms and equipment, including seven AK-47 assault rifles, three machine guns, a rocket-propelled grenade launcher and other weapons as well as a GPS receiver and other equipment.

They were from Somalia and Yemen, authorities said.

The Gibe was flying an Ethiopian flag.

Last month, the navy drew criticism after sinking a Thai fishing trawler that had been commandeered hours earlier by pirates.