The Indian Navy in another successful anti-piracy operation in the Gulf of Aden Saturday foiled an attack on an Ethiopian merchant vessel and arrested 23 Somali and Yemeni pirates, news reports said, according to dpa. Pirates on two boats had surrounded the merchant vessel MV Jibe, 160 nautical miles east of Aden, when the Indian navy warship INS Mysore intervened and staved off the attack, the IANS news agency reported. "Around 12 noon, INS Mysore received a SOS from the Ethiopian vessel, that it was under attack from two vessels," a navy spokesman told the IANS. "Armed choppers with marine commandos immediately flew to the rescue and INS Mysore also started to close in. The commandos broke off the attack by the pirates and stopped two boats carrying 12 Somalis and 11 Yemenis," he added. After the gunbattle, the naval commandos also boarded the pirates' boats and seized seven AK-47 automatic rifles, a grenade launcher and other arms and ammunition. The pirates were being held on board of the INS Mysore while the legalities of their disembarkation and prosecution are being worked out, the report said. The Indian media hailed it as a "major breakthrough" in the world's most dangerous waters off Somalia that regularly witnesses attacks by the sea brigands.