SAN ANTONIO – A Texas man wearing a hat supporting former President Donald Trump punched a poll worker who told him that wearing items supporting a candidate was prohibited at polling places, a sheriff said Friday.

The poll worker, who was a 69-year-old man, was treated at the scene Thursday and returned to his polling post at a library in San Antonio on Friday, officials said. The suspect was arrested for assault on an elderly person and could face additional charges, Bexar County Sheriff Javier Salazar said.

The alleged attack occurred at the end of the first week of early voting in Texas, where long lines formed outside some polling stations.

Both the sheriff and the county elections director urged voters to remain calm and patient during the sometimes long waits in the election, which they described as contentious.

“Thankfully there was nothing life-threatening about the incident, but it was still an ugly incident,” Salazar said.

The suspect, identified as Jesse Lutzenberger, remained in jail Friday evening, according to Bexar County. No attorney was listed in jail records and a phone number for Lutzenberger’s home could not immediately be found Friday.

Texas law prohibits wearing clothing for or against a candidate at a polling station because it is considered campaigning. According to an affidavit, Lutzenberger entered the polling station wearing a red baseball cap with the words “MAGA or TRUMP” written on it.

After being told he had to remove his cap in the voting area, Lutzenberger did so and cast his vote, Salazar said. He then put the cap back on before leaving and the clerk again asked him to remove the cap while he was in the building.

According to Salazar, as the clerk escorted him out of the library, Lutzenberger allegedly threw an elbow or arm back toward the clerk and then turned to punch him in the face several times.

The employee was treated at the scene by emergency medical personnel, said Bexar County Elections Administrator Jacque Callanen.

Salazar said there have been “several” incidents in which voters wore prohibited clothing or hats at polling stations but then removed them when the state law was explained to them.

“There’s nothing here worth getting hurt or going to jail for,” he said.