San Francisco ? Travel executives say the nation’s $91 billion foreign tourism industry is in peril because of a growing perception overseas that the United States has become “Fortress America.”

In the year after the terrorist attacks of Sept. 11, 2001, 66 million fewer visitors tried to enter the United States, according to Immigration and Naturalization Service figures. And those who did try were sent back home at a higher rate than the year before.

Travel industry executives complain that the post-Sept. 11 security crackdown at airports — especially some widely publicized incidents in which visitors were searched, interrogated and put on a plane back home — has discouraged tourism.

“There is an impression being made that we are creating a Fortress America,” said Rick Webster, a spokesman for the Travel Industry Association of America.

INS officials recognize the concerns but say their first priority is to secure all borders. “We’re not trying to discourage foreign tourists, but they need to make sure their documents are in good standing,” said INS spokesman Francisco Arcaute in Los Angeles. “After 9-11, we have to look into any possible visa problem.”

Travel to the United States was down 17 percent in the first six months of 2001, and more than 345,000 tourism-related jobs have been lost since the attacks, about a third of which served foreign tourists, according to the travel industry group.

INS figures show 700,807 people were denied entry between September 2000 and September 2001 at airports, borders and ports — one of every 714 trying to enter. During the 12 months after the attacks, 733,440 visitors, or one of every 625 people, were turned away.

The visitors include students, refugees and vacationers, many of whom spent considerable amounts of money to reach the United States.

Many rejections are happening under the radar. Decisions by INS inspectors at airports are final, and tourists have no right to legal counsel once inside an airport’s immigration sector. Most rejected travelers are quickly sent home and not heard from again.

“You don’t have any rights once they’ve got their claws into you,” said New Zealander Maggie Anderson, whose treatment at the Los Angeles airport over the summer made front-page headlines in her home country.

Anderson, a 51-year-old former flight attendant and frequent U.S. visitor, was handcuffed and made to spread her legs for a rubber-glove search after an inspector noticed she once overstayed her visa by eight days four visits previously.

After 21 hours of questioning in an INS detention center, she was sent back to New Zealand, where she got her paperwork in order. A week later and another plane ticket poorer, she was able to reunite with her American husband in California.

“I’m not knocking what they are trying to do,” Anderson said. “But my fear is they’re wasting their time on the wrong people.”