LUSAKA, Zambia (AP) _ AIDS, not war, has turned Africa into a ``killing field'' and will wipe out enough adults to create 13 million orphans in the next 18 months, the United Nations children's agency said Wednesday.

Such cataclysmic statements at the 11th international AIDS in Africa conference were aimed at prodding African governments _ which spend more on defense than on health _ to act against the scourge of the continent.

Africa is home to two-thirds of the world's 31 million HIV-infected people. Last year, AIDS killed 2 million Africans, outstripping deaths from armed conflicts on the continent 10-1, said the children's fund, called UNICEF.

In 15 years, AIDS has killed 11 million Africans, more than 80 percent of the world's AIDS deaths.

``By any measure, the HIV-AIDS pandemic is the most terrible undeclared war in the world, with the whole of sub-Saharan Africa a killing field,'' UNICEF executive director Carol Bellamy said on the conference's third day.

Ninety percent of the world's AIDS orphans live in Africa, and most suffer ``alarmingly higher rates of malnutrition, stunting and illiteracy'', UNICEF said. They often die of neglect and are victimized by the stigma surrounding the disease.

UNICEF's figures come from UNAIDS, a Geneva-based organization of epidemiologists and statisticians who study AIDS.

Jim Carmichael, a UNAIDS representative in New York, said the group estimates how many children will become orphans based on anonymous HIV testing of pregnant women at prenatal clinics. Then the group looks at whether the rates of HIV in that country are staying stable, increasing or decreasing, he said.

``In most places it's stable or increasing. There are very few places that it's decreasing,'' he said.

The number of child-headed households is rising sharply, the UNICEF report said.

In many southern African nations up to 25 percent of adults are infected with the AIDS virus _ the highest prevalence in the world. In Zambia alone, 90,000 AIDS orphans have been left to fend for themselves on the streets.

Bellamy said decades of gains for child survival and development are being wiped out by the disease.

Lack of AIDS education is part of the problem, the group said.

More than a quarter of adolescent women south of the Sahara _ the group most at risk from infection with the HIV virus that causes AIDS _ were unaware of any effective way of avoiding the disease, research has shown. In southern Africa, more than 30 percent of young women felt a healthy-looking person could not be a carrier.

The threat has been worsened, Bellamy said, by the lack of commitment from political leaders to fight AIDS. It amounts to a ``conspiracy of silence'' to hide the seriousness of the crisis from ordinary people, she said.

The United States spends $880 million fighting about 40,000 new AIDS cases a year. All of Africa spends about $150 million fighting 4 million new cases a year, and only one-tenth of the expenditure comes from governments, Bellamy said.

She said African governments must mobilize community education as a top priority. She called for them to set goals for the year 2002, including:

_ making adolescent women aware of how to protect themselves.

_ giving up to 70 percent of pregnant women access to voluntary and confidential testing.

_ encouraging HIV-positive mothers to seek treatment to block mother-to-child transmission.

_ making sure local governments can provide food, education and basic health care for the 13 million AIDS orphans.

``We can achieve these goals only with the sustained support of officials at the highest level,'' Bellamy said.

Wednesday's speakers also touched on a related topic: sexual exploitation of children.

A report earlier this week showed that young girls are at special risk for HIV infection _ partly because of the belief among many sexually active men that young girls are ``safe,'' and even that sex with a virgin can cure AIDS.

Marvellous Mhloyi, a population and family planning researcher from Zimbabwe, called for governments to pass harsher laws to protect children from exploitation.

Emma Tuahepa, 24, of Namibia, told the conference she was infected with HIV during her first sexual encounters while at school.

``I didn't know anything about sex,'' she said. ``The guy who infected me introduced me to sex. It is time to tell our children the truth.''