BANGKOK, Feb. 4 (Xinhua) -- The annual Cobra Gold multinational military exercises among Thailand, the United States, Japan, Singapore and Indonesia started Wednesday in Thailand's Northern province of Chiang Mai.

    Cobra Gold 2009 marked the 28th year of a regularly-scheduled joint and combined multilateral military exercise which has become the most visible and largest military cooperative effort in the Pacific region, said a statement issued by the U.S. Embassy to Thailand.

    Eighteen countries have been invited to observe this year's Cobra Gold, including Australia, Brunei, France, Italy, United Kingdom, Bangladesh, India, Philippines, Cambodia, China, Canada, Germany, South Korea, Laos, Nepal, Pakistan, Vietnam and Mongolia.

    U.S. Deputy Chief of Mission James F. Entwistle said at the opening ceremony that Cobra gold was unparalleled in preparing their militaries for the real-world priorities of peace support, stability and reconstruction, humanitarian assistance and combat operations.

    There are 11,637 service members participating in the Cobra Gold exercise this year. Among them 4,034 are from Thailand, 7,271from the United States, 113 from Indonesia, while the rest from Singapore and Japan.

    The military exercise will consist of a computer-simulated command post exercise, field training exercises, and humanitarian and civil assistance projects.

    Cobra gold will be held on Feb. 4-13 in many locations over Thailand.