( CNN ) -- A U.S. Navy ship came to the rescue of an oil tanker in the Indian Ocean on Saturday after four suspected pirates climbed aboard . The Japanese-owned MV Guanabara reported it was under attack Friday afternoon 328 nautical miles southeast of Oman , the Navy said . The Guanabara had 24 crew members aboard . The warship USS Bulkeley , assigned to the Combined Maritime Forces ' CTF-151 counter-piracy mission , was directed to intercept the Guanabara , supported by the Turkish warship TCG Giresun of NATO 's counter-piracy task force . After Guanabara 's master confirmed to the Bulkeley that his crew had taken refuge in the ship 's citadel room , or secure compartment , the Bulkeley 's specialist boarding team climbed aboard Saturday , detained the four men and secured the vessel , the Navy said . There was no exchange of fire at any time during the operation , and an SH-60 Seahawk helicopter supported the boarding team from the air , the Navy added . Officials said they are still deciding what to do with the suspected pirates . The U.S. Navy did not disclose the nationalities of those detained or where they were being taken . `` Through our mutual cooperation and shared coordination , CTF-151 and our partner organizations has prevented the kidnapping of legitimate mariners who sought only to go peacefully about their business , '' said CMF 's counter-piracy commander , Commodore Abdul Alheem . `` Today , there will be a merchant ship sailing freely that would not be doing so were it not for the efforts of CTF-151 . '' The Combined Maritime Forces is a naval partnership of 25 member nations including the United States that works to disrupt piracy and armed robbery and improve security in international waters off the Middle East .
A helicopter from the USS Bulkeley detained the four suspected pirates . There was no exchange of fire . Officials have not decided what to do with them .