The Defense Department is setting up two more military buffer zones along the southwestern U.S. border with Mexico. That brings to four the number of "National Defense Areas" where U.S. military personnel can temporarily detain undocumented migrants for trespassing on what are now considered to be extensions of U.S. military bases.
U.S. military personnel operating in the buffer zones do not carry out law enforcement duties, but can temporarily detain any trespassers, as they would at any military base, until they are transferred to U.S. Customs and Border Protection personnel.
The Air Force announced in a news release Wednesday that a 250-mile stretch of the border in Texas along the Rio Grande River in Cameron and Hidalgo counties will be transferred from the International Boundary and Water Commission and be considered a part of Joint Base San Antonio, Texas.
Another buffer zone will be established in western Arizona and will be considered a part of Marine Corps Air Station, Yuma, according to a U.S. official.
The Marine Corps has not yet formally made an announcement about the establishment of the new National Defense Area attached to the Yuma installation, which the official said would extend for 100 miles.
Previously, the Pentagon had established the Texas National Defense Area -- covering 63 miles -- attached to Fort Bliss, Texas, and the New Mexico National Defense Area -- covering 170 miles -- attached to Fort Huachuca, Arizona.
The Air Force said Wednesday that members of the Joint Task Force-Southern Border, under the direction of U.S. Northcom will operate within the zones.
"Their responsibilities include enhanced detection and monitoring through stationary positions and mobile patrols, temporarily detaining trespassers until they are transferred to the appropriate law enforcement authorities, and supporting the installation of temporary barriers, and signage to secure the area," the Air Force said in a statement.
Last month, a federal judge dismissed trespassing charges against 98 undocumented immigrants who were arrested in one of the National Defense Areas in New Mexico after finding the federal government had failed to demonstrate they knew they were entering the restricted zone.
As of about mid-May, the Justice Department said 60 people had pleaded guilty to charges stemming from illegally entering the National Defense Area in western Texas.