PERTH, Australia -- An intense search is underway in the southern Indian Ocean for signs of possible debris from the Malaysia Airlines Boeing 777 that went missing on March 8. Here's a list of the countries taking part and what they have sent to help the search overseen by Australia from a military base near the southwestern city of Perth.

AUSTRALIA

Two military P3 Orion planes; four non-military jets; the navy supply ship HMAS Success.

CHINA

Two Ilyushin IL-76 planes; warships Kunlunshan, Haikou and Qiandaohu; icebreaker Snow dragon.

JAPAN

Two P3 Orion planes.

NEW ZEALAND

One military P3 Orion plane.

UNITED STATES

One military P8 Poseidon plane.