Federal immigration officials have released hundreds of detainees from immigration detention centers around the country in recent days in a highly unusual effort to save money as automatic budget cuts loom in Washington, officials said Tuesday.

The government has not dropped the deportation cases against the immigrants, however. The detainees have been freed on supervised release while their cases continue in court, officials said.

But the move angered some Republicans, including Rep. Robert Goodlatte of Virginia, chairman of the House Judiciary Committee, who said the releases were a political gambit by the Obama administration that undermined the continuing negotiations over comprehensive immigration reform and jeopardized public safety.

"It's abhorrent that President Obama is releasing criminals into our communities to promote his political agenda on sequestration," said Goodlatte, who is running the House hearings on immigration reform. "By releasing criminal immigrants onto the streets, the administration is needlessly endangering American lives."

A spokeswoman for Immigration and Customs Enforcement, or ICE, an arm of the Department of Homeland Security, said the detainees selected for release were "noncriminals and other low-risk offenders who do not have serious criminal histories."

Officials said the releases, which began last week and continued on Tuesday, were a response to the possibility of automatic governmentwide budget cuts, known as sequestration, which are scheduled to take effect on Friday.

"As fiscal uncertainty remains over the continuing resolution and possible sequestration, ICE has reviewed its detained population to ensure detention levels stay within ICE's current budget," the agency's spokeswoman, Gillian Christensen, said in a statement.

The agency's budget for custody operations in the current fiscal year is $2.05 billion, officials said, and as of Saturday, ICE was holding 30,773 people in its detention system.

In a news briefing Monday before the releases were announced, Homeland Security Secretary Janet Napolitano indicated that sequestration would affect detention policy. "I'm supposed to have 34,000 detention beds for immigration," she said. "How do I pay for those?"

Immigration officials said Tuesday that they had no plans to release substantially more detainees this week, though they warned that that decision depends on the outcome of budget negotiations.

They refused to specify exactly how many detainees were released, or where the releases took place. But immigrants' advocates around the country have reported that detainees were freed in several places, including Hudson County, N.J.; Polk County, Tex.; Broward County, Fla.; New Orleans; and from centers in Alabama, Arizona, Georgia and New York.

While immigration officials occasionally free detainees on supervised release, immigration advocates said that the surge of recent releases — so many in such a short span of time — was extraordinary.

Under supervised release, defendants in immigration cases have to adhere to a strict reporting schedule that might include attending appointments at a regional immigration office as well as wearing electronic monitoring bracelets, officials said.

Advocacy groups, citing the cost of detaining immigrants, have for years argued that the federal government should make greater use of less expensive alternatives to detention for low-risk defendants being held on administrative charges.

One such group, the National Immigration Forum, estimated last year that it cost from $122 to $164 a day to hold a detainee in the federal immigration system, while alternative forms of detention could cost from 30 cents to $14 a day per immigrant.

Among those released in the past week was Anthony Orlando Williams, 52, a Jamaican immigrant who spent nearly three years in a detention center in Georgia. "I'm good, man," he said. "I'm free."

Immigrants' advocates applauded the releases but pressed the Obama administration to do more, including leaving alone immigrants accused of low-level crimes and administrative immigration violations.

But Sen. Jeff Sessions, R-Ala., of the Senate Judiciary Committee, which is also holding immigration hearings, said the releases "lessened the chances" that legislators might reach a bipartisan accord on immigration reform.