President Donald Trump renewed his call for a wall on the southern border after U.S. Border Patrol Agent Rogelio Martinez was killed and his partner injured while on patrol Sunday.
Martinez and his partner were "responding to activity" near Interstate 10 in Van Horn, Tex. on Sunday, the Washington Post reports.
Martinez’s partner called for help. Other agents arrived, provided medical care and took them to a hospital.
Martinez died of his injuries; his partner, who was not identified, remained in the hospital in serious condition, officials said.
Martinez, a 36-year-old from El Paso, had been a border agent since August 2013.
The agents were not injured from gunshots, and additional information is expected to be released on Monday. While details remain unclear, Art Del Cueto, vice president of the National Border Patrol Council labor union, said "we strongly believe rocks were what was used."
Trump tweeted that the United States "will, and must, build the Wall," and said "We will seek out and bring to justice those responsible."
Sen. Ted Cruz (R., Texas) also released a statement on Twitter where he expressed his condolences and also called for increased border security.
"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," Cruz said.
Acting Secretary of Homeland Security Elaine Duke said in a statement, "We are fully supporting the ongoing investigation to determine the cause of this tragic event."
The U.S. Customs and Border Protection website lists 38 patrol agents killed in the line of duty since 2003.