Hundreds of Muslim Immigrants Rounded Up in Calif. Hundreds of Muslim Immigrants Rounded Up in Calif. Wed Dec 18, 8:47 PM ET Add Top Stories - Reuters to My Yahoo! By Jill Serjeant LOS ANGELES (Reuters) - Hundreds of Iranian and other Middle East citizens were in southern California jails on Wednesday after coming forward to comply with a new rule to register with immigration authorities only to wind up handcuffed and behind bars. Shocked and frustrated Islamic and immigrant groups estimate that more than 500 people have been arrested in Los Angeles, neighboring Orange County and San Diego in the past three days under a new nationwide anti-terrorism program. Some unconfirmed reports put the figure as high as 1,000. The arrests sparked a demonstration by hundreds of Iranians outside a Los Angeles immigration office. The protesters carried banners saying "What's next? Concentration camps?" and "What happened to liberty and justice?." A spokesman for the Immigration and Naturalization Service said no numbers of people arrested would be made public. A Justice Department (news - web sites) spokesman could not be reached for comment. The head of the southern California chapter of the American Civil Liberties Union (news - web sites) compared the arrests to the internment of Japanese Americans in camps during the Second World War. "I think it is shocking what is happening. It is reminiscent of what happened in the past with the internment of Japanese Americans. We are getting a lot of telephone calls from people. We are hearing that people went down wanting to cooperate and then they were detained," said Ramona Ripston, the ACLU's executive director. JAILS OVERFLOWING One activist said local jails were so overcrowded that the immigrants could be sent to Arizona, where they could face weeks or months in prisons awaiting hearings before immigration judges or deportation. "It is a shock. You don't expect this to happen. It is really putting fright and apprehension in the community. People who come from these countries -- this is what they expect from their government. Not from America," said Sabiha Khan of the Southern California chapter of the Council on American Islamic Relations. The arrests were part of a post Sept. 11 program that requires all males over 16 from a list of 20 Arab or Middle East countries, who do not have permanent resident status in the United States, to register with U.S. immigration authorities. Monday was the deadline for men from Iran, Iraq, Syria, Libya and Sudan. News of the mass arrests came first in southern California, which is home to more than 600,000 Iranian exiles and their families. Officials declined to give figures for those arrested or for the numbers of people who turned up to register, be fingerprinted and have their photographs taken. "We are not releasing any numbers," said Immigration and Naturalization Service (INS) spokesman Francisco Arcaute. CALLS FOR HELP Islamic groups and the local chapter of the American Civil Liberties Union (ACLU) said they had been swamped with calls for help. INS spokesman Arcaute said those arrested had violated immigration laws, overstayed their visas, or were wanted for crimes. The program was prompted by concern about the lack of records on tourists, students and other visitors to the United States after the Sept. 11 hijack plane attacks on New York and Washington. Islamic community leaders said many of the detainees had been living, working and paying taxes in the United States for five or 10 years, and had families here. "Terrorists most likely wouldn't come to the INS to register. It is really a bad way to go about it. They are being treated as criminals and that really goes against American ideals of fairness, and justice and democracy," Khan said. The Iranian protesters said many of those detained were victims of official delays in processing visa and green card requests. "My father, they just took him in," one young man told reporters. "They've been treating him like an animal. They put him in a room with, like, 50 other people and no bed or anything." Khan said one of those in jail was a doctor, who was being sponsored for U.S. citizenship when his sponsor died. One Syrian man said he went to register in Orange County with a dozen friends. He was the only one to come out of the INS office. "All my friends are inside right now," M.M. Trapici, 45, told reporters. "I have to visit the family for each one today. Most of them have small kids."