The Berks County detention center, long the target of activists who condemned it as barbaric, is now empty of the immigrant families that it confined for two decades.

The question is whether it will stay that way.

“We’re thrilled about the families being released, but we’re on high alert and vigilant because it doesn’t mean the shutdown of Berks,” said Jasmine Rivera, a leader in the Philadelphia-based Shut Down Berks Coalition. “At any moment they could bring in new families, and the cycle could start all over again.”

Officials with U.S. Customs and Immigration Enforcement said Monday night that while no one is in custody now, the agency is evaluating the way it uses family detention centers, “which remain fully operational.”

The 96-bed Berks lockup is operated by the county through a contract with ICE.

The seven or eight families being held there were surprised to learn last week that they were leaving, and leaving fast. That meant quickly contacting family members to arrange rides or in some cases flights to places from California to New England.

For years immigration advocates maintained that all those being held could be instantly released to family members, allowed to continue fighting their asylum claims from outside of confinement. Asylum is a legal means of staying in the country, which can be granted to people who could be harmed or killed in their homelands.

“The detention of families should never happen,” said immigration lawyer Bridget Cambria, who works closely with families as executive director of ALDEA — The People’s Justice Center in Reading. “They’ll be able to seek their lawful rights from a safe place. But I remain cautious and concerned. … It could be refilled with families.”

What’s formally called the Berks County Residential Center is in Leesport, about 75 miles northwest of Philadelphia, one of three places where the federal government confines migrant children and parents together.

Its population has increased and decreased over time, rising or falling depending on the number of families entering the country and if and where the federal government decided to hold them. A year ago at this time, the center held about 40 migrant adults and children, the youngest a 6-month-old girl.

Sen. Bob Casey called the emptying of the center “a long overdue step to deliver justice to vulnerable migrant families, including children.”

The next step, he said, is to permanently close the Berks facility “so that no future family or child is forced to go through what these families have endured.”

The government also holds immigrant families at the Karnes County and Dilley city facilities in Texas. The Biden administration intends to turn those into short-term “reception centers,” the San Antonio Express-News reported, confining families only long enough to administer health screenings and COVID-19 tests and to arrange for housing.

ICE officials said they were studying how to use the centers “to safely, effectively, and efficiently process and screen families,” but provided no further details Monday night.

Critics who deride Berks as a “baby jail” have long maintained that there’s no reason to keep families locked up. They can be given notice of when to appear in court and released to family members or sponsors in the community, kept under supervision, if necessary, through phone check-ins or by monitoring devices such as ankle bracelets.

“I saw how my son suffered there and how I suffered next to him,” said one woman, identified only as Delmy, who was detained two years and whose statement was provided by the Shut Down Berks Coalition. “Close that center. No more children should be detained, no more parents should be detained.”

For years the center has faced protests, vigils, and lawsuits aimed at forcing its closure.

Gov. Tom Wolf has called the detention of families at Berks immoral, inhumane, and wrong but has said his administration lacked power to act, given the contract between the county and federal government. His administration rejected demands to evacuate families via an emergency removal order, saying that can be done only upon a finding of immediate and serious danger to life or health.

The state Department of Human Services has said that as long as the agency retains power to inspect the center, it can ensure it is safe and providing proper care. A removal order would not free families from federal custody but would end the department’s ability to monitor conditions, the agency has said.

Amnesty International has condemned Berks and similar facilities as inhumane and expensive, saying they “undermine our country’s long history as a beacon of hope for people seeking safety.”

No one held at Berks faces criminal charges, though the center essentially operates as a jail, confining people while their cases go forward, sometimes for years.

The Shut Down Berks Coalition plans a week of action, asking people to phone Casey on Tuesday and demand that he publicly ask President Joe Biden and Vice President Kamala Harris to permanently close the Berks, Karnes, and Dilley centers. A “Call-In Day” to Wolf is planned for Wednesday, and another to the Berks County commissioners on Thursday. On Friday an “email storm” is to be aimed at the Biden administration.

“This fight isn’t over,” Rivera said. “We in Pennsylvania are committed to ending family detention nationwide. Period.”