A United States submarine torpedoed the Iranian frigate IRIS Dena in the Indian Ocean near Sri Lanka, and Sri Lanka rescued its sailors under the International Convention on Maritime Search and Rescue (SAR), 1979. Adopted under the International Maritime Organization, the convention divides the world's oceans into search and rescue regions in which coastal states coordinate operations, and obliges ships and coastal states to help people in distress regardless of nationality. India ratified it in 2001 and manages operations in the Indian Search and Rescue Region (ISRR), where the Indian Coast Guard coordinates rescues.