What began in England two decades ago as random groups of violent youths with shaved heads who called themselves "skinheads" has grown into a worldwide movement of 70,000 people in more than 30 countries, a new report by the Anti-Defamation League has concluded.

The report, "The Skinhead International, a Worldwide Survey of Neo-Nazi Skinheads," found that by espousing a crude form of Nazism and white supremacy, these groups have become one of the world's most violent right-wing forces; in the United States they have been responsible for 31 killings in the last five years.

"It is unbelievable that three generations after the Holocaust, we still hear the deadly march of Nazi thugs around the world," said Abraham H. Foxman, the Anti-Defamation League's national director. "Cruel history has taught us that we dare not ignore the first sounds of jackboots. The violent and racist skinhead movement must be countered by government, law enforcement and all decent people."

The survey, based on 18 months of research and made public today, is the eighth report on skinhead activity produced by the Anti-Defamation League, and the most extensive. By tracking skinhead activities in 33 countries, the report found that while skinheads remain essentially members of disparate groups, they are linked by neo-Nazi ideology, hatred of non-Aryan ethnic groups and a willingness to commit violence.