A U.S. Border Patrol agent was wounded after being struck by a bullet fired from Mexico, authorities said Wednesday.

The agent, whose name was not released, was shot from the Mexican side of the Rio Grande River near Brownsville where he was assigned to patrol it by boat, according to the Brownsville Herald.

U.S. Customs and Border Protection spokesperson Marcelino Medina said in the agent suffered a non-lethal injury from a caliber weapon after an assault from the Mexican side.

“On Tuesday, December 26, 2017, a Border Patrol Agent assigned to the Riverine Unit sustained a non-life threatening injury from a small caliber weapon resulting from an assault originating from the Mexican Riverbank,” Medina said. “The agent suffered a grazing wound to the back of his head as a result of the incident and has been medically evaluated and released.

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