MACAO, July 14 (Xinhuanet) -- The Macao police have busted an underground casino operated at a downtown hotel, local media reported on Thursday.

    The Macao Post quoted police sources as saying that four suspects involved in the illegal gaming case have been arrested on the spot.

    The police conducted the raid on an emergency call made by a businessman who had lost some 4 million Hong Kong dollars at the clandestine casino, the sources told the newspaper.

    Police believed that the illicit gaming system has been running for over two months and the gang had regularly changed hotels to avoid the detection by the authorities.

    The gang mainly targeted Chinese mainlanders and assumedly drugged the customers to cheat them out of their money, said the newspaper report.

    Gaming business is legal in the special administrative region where 17 licensed casinos are currently operating. Enditem