May 25 (UPI) -- The U.S. Customs and Border Protection agency said one of its officers fatally shot an undocumented woman in the head this week after he was allegedly attacked by a group of immigrants along the Texas-Mexico border.
The CBP said initial reports indicate that the agent was alone when he tried to apprehend the group.
"He came under attack by multiple subjects using blunt objects," the agency said in a statement. "The agent fired at least one round from his service issued firearm, fatally wounding one of the assailants. The rest of the group fled the scene."
The names of the Border Patrol agent and the victim have not been released.
The shooting is under investigation. Meanwhile, witnesses dispute the agency's account, according to The New York Times.
Marta V. Martinez said she witnessed the shooting and the immigrant group didn't have weapons.
"They were on the very corner on that lot where there was a tree," Martinez told the paper. "There was no weapon. They were hiding."
Martinez posted a video on Facebook that begins moments after the shooting.
The video shows police and Border Patrol agents working to control the scene as Martinez asks them why the woman was shot in the head.
The killing comes at a time when the U.S. government is proposing an increase in militarization along the U.S.-Mexico border, which immigration activists oppose.
Karina Alvarez, founder of Laredo Immigrant Alliance, told NPR that the border doesn't need increased security.
"Our community really is in fear, we really think there should be accountability over Border Patrol agents," she said.