Iranian Americans are accusing the U.S. government of entrapment following the arrests of as many as 2,500 Middle Eastern immigrants who had voluntarily registered with the U.S. Immigration and Naturalization Service (INS).

Under a new anti-terrorism program, all males over 16 years old who are visiting the U.S. from Iran, Iraq, Libya, Sudan and Syria were ordered to register in person with the INS by Monday.

When they went to register, many of the men were arrested for not having their papers in order -- which, in some case, was caused by government backlog.

One report said between 500 and 700 people had been detained by the authorities. Another put the number as high as 2,500.

Immigration officials have not provided any figures on the number of detentions, but a spokesman for the INS defended the arrests.

"The only time the INS detains someone, independent of their ancestry and their religion, is when they have violated immigration law," said Francisco Arcaute, spokesman for the Los Angeles INS district.

But lawyers battling to get the men released say it's a case of entrapment.

"These people came to the INS centers voluntarily. They are not flight risks. They were led to believe it was routine registration and now this is the biggest trap I have ever seen," Iranian-American lawyer Sohelia Jonoubi told Reuters.
He added that the men are being held in inhumane conditions.

"The situation in the detention centres is absolutely horrifying. In one centre, they were ordered to strip down and given a strip search. They were only given a prison jumpsuit, without any underwear, T-shirts, socks or shoes. They were not given blankets. They are freezing," Jonoubi said.

On Wednesday, thousands of Iranian Americans protested outside a federal building in Los Angeles, holding signs that read "What Next? Concentration Camps?" and "Detain Terrorists Not Innocent Immigrants."

"These people were here legally, just waiting for their green card," said rally organizer Faraday Kioumehr.

In Cleveland and Houston, civil rights groups filed lawsuits on behalf of some of the man, contending that the arrests violate the intention of the program.

The National Security Entry-Exit Registration System is designed to keep track of visitors to the U.S. and was unveiled in the wake of the 9/11 terrorist attacks.

Under the same program, temporary visitors from 15 other countries, including Saudi Arabia and Pakistan, are required to register with the INS by Jan. 10, 2003.

With reports from The Associated Press and Reuters