A U.S. Navy ship has sunk a pirate "mother ship" in the Indian Ocean and captured 11 pirates, and then promptly let them go.
While those five pirates remain in custody, the 11 captured Thursday were allowed to leave in small skiffs after the mother ship was sunk. The action prompted a Pentagon spokesman to deny that the Navy had a "catch and release" policy regarding pirates.
A Naval official told ABC News that the practice of releasing pirates is not unheard of. While piracy is illegal according to international maritime law, it is considered a criminal issue, not a national security one.
If the country of the attacked ship does not want to prosecute the pirates, and if Kenya, which has signed a Memorandum of Understanding with the Naval forces, does not agree to prosecute them, there are few options as to where the suspected pirates can be held and tried.
The latest confrontation occurred when pirates on three skiffs tried to hijack the Sierra Leone-flagged commercial ship MV Evita using rocket propelled grenades and rifle fire.
The MV Evita avoided being boarded by increasing its speed and firing flares, according to a press release by the Combined Maritime Piracy Task Force.
After the ship's captain radioed for help, a Swedish patrol aircraft spotted the pirates and the USS Farragut dispatched its own plane to monitor the situation until the Navy ship could arrive.
The planes watched as the suspected pirates threw ladders and other equipment into the ocean, which was enough to convince the Farragut that the suspects posed no more pirate threat, although they were still found in possession of grappling hooks, according to the task force statement.
"After ensuring that the suspected pirates had no means to conduct any more attacks, all 11 were released on the two small skiffs, while the mother skiff was destroyed and sunk," according to a statement by the Combined Maritime Forces.
Officials from both the Navy and the U.S. Africa Command, known as Africom, consider any thwarted attack and capture a success and have stepped up efforts, along with the Combined Maritime Piracy task force, to fight piracy.
In the predawn hours of Thursday morning, the USS Nicholas was attacked by pirates who may have mistaken the heavily armed ship for a merchant vessel. After a short chase, the Nicholas sank a skiff and confiscated a mother ship, and took five pirates into custody.
ABC News has learned that an American drone launched from the Seychelles helped track and capture the attacking vessels.
"The UAVs from the Seychelles did play role," AFRICOM spokesman Eric Elliott said. "We can't discuss specifics because of security reasons. We don't want to endanger the effectiveness of these aircrafts in future missions."
Last November AFRICOM began "Operation Ocean Look" using unmanned drones launched from the Seychelles to patrol the Indian Ocean for pirates.
It's not clear what the Navy intends to do with the pirates still in custody.