Today's statement from the Bahrain-based Combined Task Force 151 said the suspected pirate skiffs were spotted about 500 nautical miles off the coast of Somalia.
A team from the guided missile frigate HMAS Melbourne boarded the boats October 15 and took nine suspected pirates into custody.
The pirates are believed to have carried out attacks on a Hong Kong-flagged supertanker and Spanish fishing vessels.
Pirate attacks have dropped in recent years off the Horn of Africa with the increase of surveillance and protection from a 29-nation naval force.
