BEIJING, Nov 30 (AP) -- The number of people contracting the AIDS virus in China is rising and infections are spreading from high-risk groups such as drug users to the general population, according to a study released Tuesday.

    The report by a U.N. agency and the Chinese Cabinet's AIDS commission called for stepped up measures to gather information on the spread of the virus in China and more prevention efforts.

    China says an estimated 840,000 of its people have HIV while 84,000 have full-blown AIDS, spread mostly through prostitution and intravenous drug use. The U.N. AIDS agency says the number of infected people in China could rise to 10 million by 2020 without more urgent action.

    "The transmission of HIV is still on the rise," said Dr. Christian Voumard, the chairman of the U.N. Theme Group on HIV/AIDS, the cosponsor of the report.

    The report added: "The HIV case reports indicate that the HIV/AIDS epidemic is spreading into the general population."

    As evidence of that, Voumard cited a higher number of women contracting the virus and a larger proportion of transmissions through sex.

    Large numbers of cases have been found in the provinces of Yunnan in the southwest and Henan in central China, as well as in the northwestern desert region of Xinjiang, according to the report.

    It said that might be due in part to more screening of commercial blood and plasma donors, as well as intravenous drug-users.

    "That is a call for stepping up prevention measures," Voumard said.

    Some parts of Henan have the world's highest rates of infection after an unsanitary blood-buying industry in the 1990s spread the virus among donors. Drug use is widespread in Yunnan, which borders heroin-producing areas of Southeast Asia.

    The report didn't explain the increase in Xinjiang, but the mostly Muslim region was one of 10 areas targeted this year in a program aimed at stemming the spread of the virus.

    Voumard said China still lacks a nationwide system to gather information on infection rates.

    The Chinese government has in recent years launched efforts to control the virus after years of denying it was a problem. But it still harasses activists who agitate for better measures.

    In April, health officials began offering free AIDS tests to anyone who wants one and free treatment for the poor. Health officials are also now encouraging pregnant women to be tested.

    In some parts of China, the report noted, as many as 5 percent of pregnant women are infected.