Border Patrol agent murdered, his partner seriously injured while on patrol near the Mexico border

A United States Customs and Border Patrol agent was killed and another injured in an apparent ambush-style attack in rural West Texas Sunday morning.

What happened?

The details surrounding the incident remain very murky as officials have been reluctant to release more details about the attack. According to a Border Patrol statement, the agents were "responding to activity” in the Big Bend patrol sector when they were attacked.

Both agents were taken to the hospital. One agent, Rogelio Martinez, died as a result of his injuries. The other agent remains in serious condition. Investigators haven’t released his name.

According Art Del Cueto of the National Border Patrol Council, it is believed the agents were attacked with rocks, though investigators haven't yet publicly confirmed that.

While the Border Patrol didn’t specify what took place, Sen. Ted Cruz (R-Texas) released a statement Sunday calling what happened an “attack.” Law enforcement officials said they were scouring the area for the individuals responsible for the attack.

The FBI is now leading the investigation. The agency told the New York Times more information will be released Monday. However, an agent in the FBI's El Paso field office told Fox News the agents were not fired upon.

Martinez, 36, began working for the Border Patrol in 2013. He was assigned to the Big Bend patrol sector, an area which covers 135,000 square miles in Texas and Oklahoma.

How did officials respond?

President Donald Trump responded by reiterating America's need for a wall on the southern U.S. border:

Cruz said in his statement:

Our condolences and prayers go out to the family and friends of Border Patrol Agent Rogelio Martinez, who was killed this morning in the line of duty. We are also praying for the full recovery of his partner, who was also attacked.

This is a stark reminder of the ongoing threat that an unsecure border poses to the safety of our communities and those charged with defending them. We are grateful for the courage and sacrifice of our border agents who have dedicated their lives to keeping us safe. I remain fully committed to working with the Border Patrol to provide them with all the resources they need to safeguard our nation.

Texas Gov. Greg Abbott (R) said:

Our prayers are with the families of this Border Patrol Agent who was killed & the other who was injured in this attack in Texas. Our resources must be increased to prevent these attacks in the future. #txlege #tcot https://t.co/60tHfoWKRq

— Greg Abbott (@GregAbbott_TX) November 20, 2017