ABOARD THE DESTROYER MURASAME (AP) -- Japanese navy sailors on a speedboat raced to a simulated suspicious boat while aircraft watched from the sky in a multinational exercise Wednesday off Tokyo's southern coast to practice intercepting weapons of mass destruction at sea.
Destroyers and surveillance aircraft, as well as coast guard ships from Japan, the U.S., South Korea and Australia, participated in the exercise, part of the Proliferation Security Initiative.
Journalists observed from the Japanese destroyer Murasame.
Wednesday's "Pacific Shield 18" exercise off the coast of the Boso Peninsula, southeast of Tokyo, simulated the halting of ships suspected of carrying materials related to weapons of mass destruction to conduct inventory checks.
Personnel from several countries took turns approaching the target ship and communicating with its crew.
Thirty countries participated in the exercise, along with 20 observers and four non-members, mainly from the Indo-Pacific region and Europe.
The initiative started in 2003 as part of Washington's efforts to block shipments of nuclear, chemical and biological weapons, and the materials and equipment needed to make them, as well as missiles that can be used to deliver them.
Japan has actively monitored offshore ship-to-ship transfers of oil allegedly involving North Korean ships, a potential violation of U.N. sanctions imposed over the North's nuclear and missile programs.
The initiative does not target any specific country, but North Korea has criticized it, calling it a provocation.