About 500 Marines from Camp Pendleton in Southern California are being deployed to Yuma, Arizona, to support security along the U.S.-Mexico border, the San Diego Union-Tribune reported Friday.

The report quoted officials from the base, stating that the troops' mission would focus on reinforcing barriers, placing signs, and monitoring and detecting activity along the border, as military personnel are not authorized to carry out civilian law enforcement activities such as searches, seizures or arrests.

However, the report noted that such deployments have been common over the past year under U.S. President Donald Trump, especially in areas along the Arizona border, including near Yuma, which had been designated a National Defense Area (NDA) as part of Trump's crackdown on illegal immigration.

An NDA is a designation under the Trump administration that creates a militarized zone along the southern border with Mexico. This transfers land to the Department of Defense for enhanced security, including military-grade surveillance, drones, sensors, troops and barriers such as walls and razor wire.

The designation allows troops to detain people suspected of trespassing onto military bases and turn them over to federal law enforcement. Those arrested may face federal trespassing charges.

The newest militarized border zone is located in California's Imperial County and the eastern parts of San Diego County.