Los Angeles ? Gisroo Mohajeri clutched her pregnant belly on the steps of the downtown federal building and uttered a mother’s lament: “I feel so guilty,” she sobbed.

Three days after urging her 16-year-old, Iranian-born son to voluntarily register with federal immigration officials under a new program, he now faces deportation proceedings.

Mohajeri and relatives of the hundreds of Middle Eastern men and teens who were detained in California this week say they feel betrayed by the country that once offered them a safe haven.

A special registration program requires male visa holders age 16 and older from countries considered high risk for terrorists to report to immigration offices to be fingerprinted and photographed. Visa holders from Iran, Iraq, Libya, Sudan and Syria were to register by Monday.

Since then, about 400 people have been detained in Southern California, said Jorge Martinez, a Justice Department spokesman. Southern California is home to an estimated 800,000 Iranian-Americans and 85,000 Iraqi-Americans. A minimal number were detained elsewhere in the United States.

By Friday, 23 remained in custody nationwide, Martinez said. Their names came up in law enforcement databases in connection with various crimes, he said.

Sean Igbal, bottom left, Louai Jalabi and Ashraf Ibrahim say their evening prayers during an emergency town hall meeting of the Council on American-Islamic Relations of Southern California in Buena Park, Calif. The meeting was called to discuss new INS registration requirements.

On Wednesday, thousands of Iranian-Americans protested the arrests outside the federal building, snarling traffic on Wilshire Boulevard. No arrests were reported.

The registration is part of new federal security guidelines that resulted from the Sept. 11 terror attacks. In the next phase, male visa holders from 13 additional countries — including Afghanistan, Lebanon and North Korea — will be required to register by Jan. 10. Males from Saudi Arabia and Pakistan must register by Feb. 21.

The regulation applies to those here on temporary visas, including tourists and students. Naturalized citizens, diplomats, green card holders and those who were granted political asylum are exempt.