The Justice Department says agents can’t access 2.5 miles of the border and a boat ramp in Eagle Pass.

The Texas National Guard and state troopers have blocked U.S. Border Patrol agents from a 2.5-mile stretch of the Rio Grande in Eagle Pass, preventing federal agents from patrolling that part of the border, according to a court filing by the U.S. Department of Justice, escalating the clash between state and federal authorities on the Texas-Mexico border.

On Wednesday night, troopers and National Guard members began to take “full control” of the 47-acre Shelby Park, erected concertina wire and fencing at the park to close off access to the public, Eagle Pass Mayor Rolando Salinas said. He added that he was told that the park would be closed indefinitely and the state took the action to prevent immigrants from illegally crossing into Texas.

State officers and National Guard members also have denied Border Patrol agents entry to the park, where agents routinely used a boat ramp to launch their boats to patrol the Rio Grande, the filing says. There is also a staging area at the park that Border Patrol agents use to inspect migrants who have been apprehended in this part of the border, the filing says.

In the filing, the DOJ is asking the U.S. Supreme Court to intervene in an ongoing legal battle between the state and the federal government and overrule a 5th Circuit Court of Appeals ruling that prevents Border Patrol agents from cutting the concertina wire Texas has strung along the Rio Grande.