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.
The releases, which have taken place over the past few days, were approved "in order to make the best use of our limited detention resources in the current fiscal climate and to manage our detention population under current congressionally mandated levels," Gillian M. Christensen, a spokeswoman for Immigration and Customs Enforcement, an arm of the Department of Homeland Security, said in a statement. The budget cuts, also called the sequester, are scheduled to take effect Friday.
The agency, Ms. Christensen added, "is continuing to prosecute their cases in immigration court and, when ordered, will seek their removal from the country."
Officials did not reveal how many detainees were released or where the releases took place, but immigrants' advocates around the country have been reporting that hundreds of detainees were freed in numerous locations around the country, including Hudson County, N.J.; Polk County, Texas; Broward County, Fla.; and New Orleans; and from centers in Arizona, Alabama, Georgia and New York.
While immigration officials occasionally free detainees on supervised release, this mass release — so many in such a short span of time — appears to be unprecedented in recent memory, immigration advocates said.
Under supervised release, defendants in immigration cases have to adhere to a strict reporting schedule that might include attending appointments at their regional Immigration and Customs Enforcement office as well as telephonic and electronic monitoring, immigration officials said.
Immigrants' advocacy groups, citing the cost of detaining immigrants, have for years argued that the federal government should make greater use of practical and less expensive alternatives to detention, particularly for low-risk defendants being held on administrative charges.
The National Immigration Forum estimated last year that it cost the federal government between $122 and $164 per day to hold a detainee in its immigration system. In contrast, the organization said, alternative forms of detention could cost between 30 cents to $14 per day per immigrant.
Advocacy groups applauded the releases but pressed the Obama administration to do more, including adhering more closely to its declared enforcement priorities like focusing on serious criminals and those who pose a threat to public safety, rather than immigrants accused of misdemeanors and administrative immigration violations.
"It shouldn't take a manufactured crisis in Washington to prompt our immigration agencies to actually take steps towards using government resources wisely or keeping families together," said Carolina Canizales, a leader of United We Dream, the nation's largest organization of young illegal immigrants.
At a White House news briefing on Monday, Janet Napolitano, the homeland security secretary, seemed to hint at the move. "All I can say is, look, we're doing our very best to minimize the impacts of sequester," she told reporters. "But there's only so much I can do. I'm supposed to have 34,000 detention beds for immigration. How do I pay for those?"
