Border Patrol agents exchanged shots with suspected Mexican cartel members Monday along the southern border.

An incident in Texas’ Rio Grande Valley involved a gunshot being fired from the southern side of the U.S.-Mexico border toward border agents, the Washington Examiner reported.

According to federal and state law-enforcement officials, U.S. Border Patrol Agents returned multiple shots.

The Examiner was told by sources that the incident took place in Fronton, Texas. The Mexican cartel suspected of being behind the first bullet is suspected to be responsible. The bullet did not strike any Border Patrol agents.

Chris Olivarez of the Texas Department of Public Safety posted photos and videos of the heavily armed shooter.

“VIDEO: Earlier today, @TxDPS responded to assist the US Border Patrol after agents received gunfire from cartel members in Mexico while patrolling in Fronton, Starr County. DPS Drone Operators captured the gunmen fleeing Mexico due to military presence, & seeking refuge on an island between the US & Mexico. The State of Texas will continue to monitor the area closely & use every resource available to prevent transnational threats to our law enforcement partners & the homeland,” Olivarez posted.

According to two officials who spoke with The Examiner, after Donald Trump’s win, the cartel gave their members the “green lights” to shoot at federal law enforcers.

During the campaign, Trump promised that border security, deportation, and criminal records were his top priorities.

Ali Bradley, NewsNation reporter, told five border agents in an online chat that the area where the shooting occurred on Monday is called “Cartel Island” because “there were a lot of problems with the cartel”.

“Being fired on by the cartel is not necessarily unprecedented,” Bradley said. “Unfortunately, my agents are texting me saying, ‘Unfortunately, we’re used to that.'”

Fronton Island, located in Starr County, Texas, is an uninhabited island at the center of a territorial dispute, with conflicting ownership claims from both Texas and Mexico, according to Newsweek.

Art Del Cueto Vice President of the National Border Patrol Council, told Bradley “The violence will continue because it is a billion-dollar industry and they have to keep their money.”

The reported shooting occurred the same day that Trump told House Republicans he would be focusing on the border “more than anything”.