Los Angeles ? Federal agents arrested 81 people who used phony identification to get jobs with high level security clearances at Southern California airports, officials said Friday.

The raid Thursday uncovered immigration violations and document fraud but no connections to terrorist groups, authorities said. The action was part of a national sweep started last fall known as “Operation Tarmac.”

Most of the alleged violators were Hispanic immigrants employed as baggage handlers, janitors and maintenance workers. They were among some 40,000 Southern California airport employees investigated because of their access to restricted areas.

U.S. Atty. Debra W. Yang said the safety of the traveling public “required us to examine those with access to the most secure portions of the airports.”

But immigrants’ rights groups and unions said the government should make it easier for illegal workers to get proper papers instead of arresting them.

“It’s a disgrace,” said Eliseo Medina, executive vice president of the Service Employees International Union. “President Bush is punishing hard-working immigrants for the crimes committed last September by terrorists.”

More than 150 protesters from labor unions representing immigrant workers marched outside the federal courthouse Friday.

Nationwide, hundreds of workers with access to high-security areas of airports have been arrested in sweeps since Sept. 11.

Most of the cases involved charges of using phony Social Security numbers, lying about past criminal convictions or being in the United States illegally.