A Border Patrol agent pursuing a group of migrants in a wooded area near the Texas-Mexico border on Friday fired several shots at an armed man who later identified himself as a militia member.

Border Patrol spokesman Omar Zamora said agents had been chasing a group of migrants east of Brownsville Friday afternoon when an agent saw a man holding a gun near the Rio Grande. The agent fired four shots, but did not hit the man. The man then dropped his gun and identified himself as a member of a militia. Zamora said no other details were immediately available.

Cameron County Sheriff Omar Lucio, whose agency is involved in the investigation, said the incident occurred on private property and it appeared the man had permission to be there. He was not arrested, Lucio said.

The man, whose name has not been released, was wearing camouflage and carrying a long arm that was either a rifle or shotgun, Lucio said. The agent had lost the group of migrants when he turned around and saw the man holding the weapon.

An unknown number of militia members have come to the Texas border following a surge in illegal immigration this summer.

But Lucio said, “We really don’t need the militia here.” He recognized they have the right to carry weapons, but noted that with the Border Patrol, Texas Department of Public Safety and local law enforcement, there are enough agencies working to secure the border. Governor Rick Perry also called as many as 1,000 National Guard members to the border.

“It just creates a problem from my point of view, because we don’t know who they are,” Lucio said.

This month, the Border Patrol warned its agents about militia members after seven of them dressed in camouflage and carrying rifles appeared out of the dark and began helping to apprehend migrants around a canal near Mission. The agents initially mistook them for a Department of Public Safety tactical team.