Updated

More than 160 foreign nationals -- most of them illegal immigrants with criminal records -- were arrested in northern Virginia over a three-day enforcement surge involving federal, state and local police, U.S. Immigration and Customs Enforcement Director John Morton said Wednesday.

The enforcement sweep, conducted between Sunday and Tuesday, ensnared men and women from 32 countries, including eight people who had been convicted of sex offenses.

Morton announced the arrests at a news conference in Manassas, where political leaders have faulted ICE for failing to enforce the nation's immigration laws aggressively enough.

"We are dedicated to the removal of criminal offenders from our country," Morton said, arguing that ICE has removed more illegal immigrants from the country in the last two years than it ever had.

Morton's announcement failed to impress Prince William County Board of Supervisors Chairman Corey Stewart, a vocal critic of what he says is lax federal enforcement of immigration law, who called Wednesday's news conference a "dog-and-pony show."

Stewart said the statistics show that ICE routinely fails to detain known illegal immigrants even when they have been convicted of serious crimes, including felonies. He said in Prince William County alone, Prince William authorities have turned over 3,000 criminal aliens to ICE in recent years, and ICE refuses to say whether those people were detained, deported to released back into the community.

Stewart suspects that the vast majority were turned loose, based on the fact that Prince William police have ended up re-arresting 346 of them.

"This is certainly not enough," Stewart said of the enforcement sweep. "ICE and the federal government will show that they are serious about dealing with criminal illegal aliens when they begin to hold criminal illegals in custody until they are deported."

Of the 163 arrests in the recent enforcement action, roughly 130 were people with criminal records -- 85 for felonies and 45 with misdemeanors, Morton said.

While the enforcement action targeted illegal immigrants with criminal records, more than 30 of those arrested had no criminal convictions but were nevertheless in the U.S. unlawfully, according to ICE.

Morton said that while their focus is criminal aliens, "we're not going to turn a blind eye" to others who cross paths with ICE and who are in the country illegally but have not committed any other offense.

Stewart said the results of the enforcement surge are misleading. The few statistics that the county has been able to obtain from ICE show that only rarely does ICE detain and deport illegal immigrants for anything but the most serious felonies.

While ICE places its highest priorities on those who have committed the most serious crimes, Morton said any criminal offense by a foreign national can make that individual a target for ICE. Several of those arrested, for instance, had legal permanent resident status but committed crimes that make them deportable.

"These are not the kind of people we want walking the streets of our Commonwealth," Morton said.

Of those arrested, 60 were in Fairfax County, 37 in Prince William County and 20 in Loudoun County. Smaller numbers were arrested in Arlington County, the city of Alexandria and the outlying counties of northern Virginia.