TOKYO, April 24 (Xinhua) -- A Japan-based U.S. Navy serviceman suspected of robbing and killing a cabby last month was indicted by Japanese prosecutors Thursday.

    Olatunboson Ugbogu, 22, a crew member of the U.S. 7th Fleet's cruiser Cowpens, based at Yokosuka city of Kanagawa Prefecture south of Tokyo, was charges of robbery-murder of the taxi driver in the city.

    Ugbogu, whose credit card was found in the taxi, admitted killing the cabby after being arrested by the U.S. Navy on March 22 around central Tokyo's Gotanda train station, but denied any intent to do so.

    He told investigators that a mysterious "voice" ordered him to murder the driver, according to Kyodo News.

    Ugbogu had been out of his base without report since early March until being arrested.

    The 61-year-old cabby was found dead from knife injury on the neck in his taxi on March 19. He was an employee of a taxi company based in eastern Tokyo's Shinagawa Prefecture.

    The U.S. army earlier agreed to transfer Ugbogu to Japanese police if a murder case was built according to a bilateral security agreement between Japan and the United States.

    In another case involving the Japan-based U.S. army, a U.S. military policeman of the Kadena Air Base in southern Japan's Okinawa Prefecture was indicted Thursday over assaulting a local taxi driver on March 16.

    The 21-year-old serviceman was also charged of robbing the driver of about 8,000 yen (About 78 U.S. dollars). He was arrested with another four U.S. military family members, all youngsters, over the case.