Texas state officials this week abruptly blocked federal U.S. Border Patrol agents from entering and patrolling a public area in the border town of Eagle Pass where they typically first encounter migrants who cross the Rio Grande illegally, two U.S. officials told CBS News on Thursday.

After seizing control of Shelby Park in Eagle Pass, Texas National Guard units deployed by Republican Gov. Greg Abbott have prevented Border Patrol agents from entering the area, the federal officials said. Border Patrol has used the park in recent weeks to hold migrants in an outdoor staging area before they are transported for further processing, including last month, when illegal crossings soared to record levels.

Earlier Thursday, Texas state officials prevented Border Patrol boats from patrolling that area, one of the officials added, requesting anonymity because they were not authorized to talk to the press.