WASHINGTON - In recent months, newly created teams of federal agents have arrested thousands of illegal immigrants who’ve lived and worked in the United State for years without interference. Most have been deported immediately.

Since October, 13,089 immigrants have been detained, a more than 60 percent increase from the same period in 2004. The arrests peaked in May, when agents picked up a record 1,600 people nationwide, including from the states of Nevada, Texas, New Jersey and California, which have large immigrant populations.

Immigrant-rights advocates called the sweeps excessive and heavy-handed, while supporters of tougher enforcement said even more must to be done to discourage illegal immigration.

"Whenever we do any sort of enforcement action, we get praise and criticism," said Dean Boyd, a spokesman for U.S. Immigration and Customs Enforcement, which is overseeing the arrests. "Immigration is a polarizing and divisive issue."

The spike in deportations comes as the Bush administration is under pressure to improve its detection of illegal immigrants inside the country, rather than concentrating its efforts largely at the U.S.-Mexico border.

ICE officials said they were arresting more immigrants because more agents had been assigned full time to find them. Since October, the number of fugitive-search teams assigned to finding immigrants where they live has increased from 18 to 38. The agency plans 14 more teams by the end of September.

Some immigrants complain of being treated harshly.

Nancy Arseno, a U.S. citizen, said her husband, Mario, was arrested two weeks ago at the family’s home in Las Vegas by a team of 15 armed officers. The officers handcuffed him even though he wasn’t resisting, and they refused to allow him to say goodbye to the couple’s six children, she said.

Arseno said the officers were polite, but she thought they should have given her husband a chance to turn himself in voluntarily.

"It didn’t need to be so dramatic," she said. "They acted like he had killed someone."

Mario Arseno, 31, came to the United States legally in 1993 on a work visa. A traveling musician from Peru, he forgot to renew his visa, his wife said, and an immigration judge ordered him deported in 1995. She said he never received any notice of the deportation, and he missed his chance to challenge it in court.

Nancy Arseno said immigration officers could have found her husband easily because the family had lived at the same address for years. "I don’t understand why they waited until now," she said. "If they really didn’t want people like my husband in the country, why did they allow him to work, pay taxes and marry a U.S. citizen?"

Immigrant-rights advocates said many of the immigrants had been living in communities for years and that their only crime was living illegally in the United States.

"The show of force is so over the top," said Cheryl Little of the Florida Immigrant Advocacy Center in Miami. "These sweeps are conducted so fast and so unexpectedly that those ensnarled have no chance to prepare for their departure."

But John Keeley, a spokesman for the Center for Immigration Studies, a research center in Washington that favors tougher immigration enforcement, called the sweeps "largely symbolic."

"The administration is responding belatedly and under intense pressure to do more about interior enforcement," Keeley said. "But you would need thousands of more officers to put a dent in the numbers."

Each year, the list of fugitive immigrants grows by more than 40,000. According to government estimates, more than 500,000 immigrants remain in the country even after they’ve been ordered to leave.

Torres said officers weren’t arbitrarily arresting people off the streets but were targeting immigrants who’d been ordered deported after exhausting all appeals. Of the 45,728 immigrants arrested since March 2003, when the first fugitive-search teams were created, 21,367 had criminal records.