Federal law-enforcement officials have issued notices ordering the protesters who have blockaded the Portland office of the U.S. Immigration and Customs Enforcement Agency to stop blocking the entrance or face arrest.

A group of protesters has blockaded the ICE offices, at 4310 SW Macadam Avenue, in Southwest Portland, for more than a week, shutting down the building.

Federal Protective Service officers began issuing notices at roughly 10:30 am today.

Blocking the entrance to the ICE building is illegal, but federal authorities also acknowledged that they have no authority over the adjacent property, according to the press release.

The majority of the encampment—which has grown to include more than 90 tents—is on property adjacent to the ICE building, but the protestors have also blocked the driveway and the front doors of the building, successfully shutting down ICE headquarters since June 17.

The Federal Protective Services did not include a deadline for when arrests would begin.

"The U.S. Attorney's Office is working with FPS and ICE to reopen the federal building on Southwest Macadam that serves many critical functions requiring public and employee access," said Billy J. Williams, U.S. Attorney for the District of Oregon, in a statement.

"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."