Defence Minister Yasukazu Hamada ordered Japan's air force on Friday to ready intelligence-gathering planes to join an international battle against piracy off the coast of Somalia, a government official said, Reuters reported. The move comes after the capture and dramatic rescue of a U.S. ship's captain last week underscored the difficulty international forces face in trying to maintain security in and around the busy Gulf of Aden. At least two P-3C planes will depart for a base in Djibouti, which borders Somalia, as soon as next month, along with about 150 crew and support personnel, a Defence Ministry spokeswoman said. They may start operations in June, Japanese media reported. There is an acute need for more aircraft to join the mission, because about 800 pirate groups operate along 3,000 km (1,900 miles) of coastline, a NATO officer has said. Japan's surveillance planes will provide information to two Japanese destroyers escorting Japanese commercial vessels in the area and may also exchange information with other nations' forces, the media said.