A Border Patrol agent fatally shot an illegal immigrant in Rio Bravo, Texas, after being attacked by four people Wednesday afternoon, the Laredo Sector station announced this evening.

"On May 23, 2018, at approximately 12:22 p.m., a lone Border Patrol Agent responded to a report of illegal activity near a culvert by Centeno Lane in Rio Bravo, Texas where he discovered a group of illegal aliens," according to a statement the sector issued on its mobile app.

"Initial reports indicate that as the agent attempted to apprehend the group, he came under attack by multiple subjects using blunt objects," it continued. "The agents fired at least one round from his service issued firearm, fatally wounding one of the assailants. The rest of the group fled the scene."

Agents called emergency responders to the scene after which three other illegal immigrants were taken into custody.

As standard practice, the FBI has opened an investigation into the incident.

The number of instances in which agents used a firearm has dropped in recent years as the U.S. Customs and Border Protection has sought to limit lethal uses of force.

In fiscal 2017, agents used firearms 17 times — down from 55 times in 2012.

There were nine firearm-related incidents in the first six months of fiscal 2018, from Oct. 1, 2017, through March 31, 2018.

Border Patrol does not publish data on the number of people who died as a result of firearm-related injuries.

In contrast, the number of assaults waged against CBP officers has skyrocketed in recent years from 373 attacks in fiscal 2014 to 847 in fiscal 2017.