A GUNMAN armed with an assault rifle has been killed after firing dozens of shots at a US Border Patrol building and its agents.

The ambush attack occurred at around 6 am on Monday outside the Border Patrol building near McAllen International Airport in Texas.

Authorities said the shooter, identified as Ryan Louis Mosqueda, 27, was killed after engaging in a shootout with federal agents and local police.

Mosqueda was reported missing from a location in Weslaco, Texas, at around 4 am, just hours before the shooting occurred.

“Then, an hour or so later, he was at that particular location opening fire at a federal building and our federal agents,” McAllen Police Chief Victor Rodriguez said.

Rodriguez said Mosqueda was carrying a backpack filled with more ammunition, authorities said.

The shooter’s last known address was in Michigan, Rodriguez said, adding that Mosqueda arrived in McAllen in a vehicle with Michigan license plates.

A motive for the shooting was not immediately disclosed.

Authorities uncovered additional firearms and ammunition in the suspect’s car, the police chief said.

Rodriguez said investigators found writing inside the suspect’s vehicle, which they believed to be in Latin.

A photo of Mosqueda’s white Chevy being towed away from the scene showed the words “Cordis Die’ written on the driver side doors.

It remains unknown if the writing is associated in any way with the shooting.

“I think I speak for everybody here, the world is much smaller than we think sometimes,” Rodriguez added.

“And it takes events like these to really wake you up and say, you know what we’re really, really tiny in terms of the world.

“The threats are always looming, they’re always present, and incidents like these make us realize that we’ve always got to be on guard.”

Rodriguez said the incident forced authorities to shut down vehicular traffic in and out of McAllen International Airport.

“We have no reason to believe at this point in time that there are any more threats in this area,” he said.

Rodriguez said no Border Patrol agents were injured.

However, a McAllen police officer, identified as Ismael Garcia, suffered an injury to his knee.

The FBI has taken the lead on the investigation.

HEIGHTENED ALERT

The violent incident comes days after the Department of Justice issued an alert saying it was closely monitoring attacks on Department of Homeland Security facilities.

“We are closely monitoring the attacks on DHS detention facilities in Prairieland, TX, and Portland, OR, and are coordinating with the USAOs and our law enforcement partners,” the Justice Department said in a social media post on Saturday.

“The Department has zero tolerance for assaults on federal officers or property and will bring the full weight of the law against those responsible.”

On the evening of July 4, several suspects were arrested in North Texas after a local police officer was shot in the neck following a shooting at an Immigration and Customs Enforcement detention facility in Alvarado.

The injured officer was treated at Fort Worth hospital and later released, the Alvarado Police Department said.

At least eight people were arrested in connection with the shooting, according to CBS News.