Could a religious ritual sacred to Muslims and Jews be threatened? If critics of circumcision have their way, it could be.

Anti-circumcision activists, calling themselves "intactivists," have called on the United Nations to label the act a human rights crime.

The move came after the recent release of a study showing that circumcision may significantly reduce the risk of HIV infection. The news was announced at the Third International AIDS Society Conference on HIV Pathogenesis and Treatment in Rio de Janeiro.

Critics say the need to do away with a human rights abuse trumps the medical data, which they consider specious. Human rights, they say, also supersede the religious principle whereby Jews and Muslims circumcise their sons.

The biblical Jewish patriarch, Abraham, became "world famous" by circumcising himself and establishing a covenant with God, said George Denniston, president of the Seattle-based Doctors Opposing Circumcision.

But, he said, "it's totally blasphemous to remove a normal body part from somebody. It totally denies that God made it." Additionally, circumcising a nonconsenting child is unfair, said Denniston, who said he has lobbied every U.S. senator on the issue.

Matthew Hess, who is organizing a letter-writing campaign to the United Nations with other activists, agreed. Hess is president of the San Diego-based, named after the "male genital mutilation" bill the group is lobbying for. The group wants to amend the 1996 law that outlawed female circumcision in this country to ban circumcision for males younger than 18.

Hess said the group has submitted the bill twice to Congress and the California State Legislature, but has so far failed to find sponsors.

For many, circumcision is a matter of religious fulfillment. The procedure is a "cornerstone" of the Jewish faith, said Samuel Kunin, a retired urologist who said he has performed more than 9,000 circumcisions.

"I can't think of any greater act of faith than to circumcise your son," said Kunin, of Los Angeles.

The act symbolizes a thread of Jewish continuity over thousands of years, linking back to Abraham, he said.

Kunin also said he has helped restore sexual activity for men through circumcision, which staves off urinary tract infections.

Patricia Leidl, media adviser for the U.N. Population Fund, a partner of the U.N. AIDS initiative, would not comment on the contention that circumcision is a human rights crime, saying it is up to particular countries to judge the matter.

Although studies linking circumcision with HIV prevention are not conclusive, "the trends are certainly pointing in that direction," she said.

In a 1999 statement, the American Academy of Pediatrics said scientific evidence shows potential medical benefits to circumcision, such as a reduced risk of sexually transmitted disease.

However, it found insufficient data to recommend it as a routine procedure.

In the same statement, the pediatricians noted more varied sexual practice and less sexual dysfunction among circumcised adult men and anecdotal reports of decreased pleasure among uncircumcised men.