Federal law enforcement officials told Occupy ICE protesters camping outside Portland’s Immigration and Customs Enforcement (ICE) offices on Monday that they must abandon their encampments or face arrest.

Federal Protective Service agents will begin handing out these flyers to demonstrators outside of ICE's headquarters in Portland. #OccupyICEPDX pic.twitter.com/KSjkxA8n3N — Shane D. Kavanaugh (@shanedkavanaugh) June 25, 2018

“It is unlawful under federal law to obstruct the entrances, foyers, lobbies, corridors, offices and/or parking lots of federal facilities,” reads the flyer Federal Protective Service agents—who are under the purview of the Department of Homeland Security (DHS)—distributed to protesters, who have blocked law enforcement agents from entering Portland’s ICE facility since last week.

According to the order, activists who obstruct the entrance to the federal building could be arrested and prosecuted in federal court.

Federal agents issued the order just hours after they slipped into the ICE building “to secure government property,” the Oregonian reported.

Despite the orders to leave, some protesters stayed outside the facility holding signs or sitting around. A few others began disassembling their tents.

Hundreds of Occupy ICE protesters demonstrated outside of Portland City Hall in Portland, Oregon, on Sunday to protest the U.S. Immigration and Customs Enforcement (ICE) agency. Many activists called for abolishing ICE because of their efforts to stop people from crossing the U.S. border illegally.

The city hall protest was part of an eight-day demonstration where activists camped outside the Portland ICE office, blocking officials from getting into the facility. The Portland ICE office had to shut its doors temporarily because of the protests.

U.S. Attorney for the District of Oregon Billy J. Williams announced Monday that his office would defend federal agents working for ICE and Federal Protective Service.

“While demonstrators have a lawful right to assemble and voice their concerns, blocking the building’s driveways or entrances is not permitted under federal law,” Williams announced in a statement.