The first group of immigrants has arrived at a new detention center deep in the Florida Everglades that officials have dubbed “Alligator Alcatraz,” a spokesperson for Republican state Attorney General James Uthmeier said.

“People are there,” press secretary Jae Williams said, though he didn’t provide further details on the number of detainees or when they arrived.

“Next stop: back to where they came from,” Uthmeier posted on the social media platform X on Wednesday. He’s been credited as the architect behind the Everglades proposal.

The account for the Florida Division of Emergency Management posted to X on Thursday that the facility was “stood up in record time under @GovRonDeSantis’ leadership & in coordination with @DHSgov & @ICEgov, Florida is proud to help facilitate @realDonaldTrump’s mission to enforce immigration law.”

Requests for additional information from the office of Republican Gov. Ron DeSantis and FDEM, which is building the site, were not returned Thursday afternoon.

The facility, at an airport used for training, will have an initial capacity of about 3,000 detainees, DeSantis said. The center was built in eight days and features more than 200 security cameras, 28,000-plus feet of barbed wire and 400 security personnel.

Immigrants who are arrested by Florida law enforcement officers under the federal government’s 287(g) program will be taken to the facility, according to an official in Trump’s administration. The program is led by Immigration and Customs Enforcement and allows police officers to interrogate immigrants in their custody and detain them for potential deportation.

The facility is expected to be expanded in 500-bed increments until it has an estimated 5,000 beds by early July.

A group of Florida Democratic state lawmakers headed to the facility Thursday to conduct “an official legislative site visit,” citing concerns about conditions for detainees and the awarding of millions of dollars in state contracts for the construction.

Federal agencies signaled their opposition Thursday to a lawsuit brought by environmental groups seeking to halt operations at the detention center. Though Trump applauded the center during an official tour this week, the filing on behalf of the Department of Homeland Security seemed to try to distance his administration from the facility, and said no federal money to date has been spent on it.

“DHS has not implemented, authorized, directed, or funded Florida’s temporary detention center,” the U.S. filing says.

Human rights advocates and Native American tribes have also protested against the center, contending it is a threat to the fragile Everglades system, would be cruel to detainees because of heat and mosquitoes, and is on land the tribes consider sacred.

It’s also located at a place prone to frequent heavy rains, which caused some flooding in the tents Tuesday during a visit by Trump to mark its opening.

State officials say the complex can withstand a Category 2 hurricane, which packs winds of 96 to 110 mph, and that contractors worked overnight to shore up areas where flooding occurred.