DALLAS (CBSDFW.COM) – Customers angry over the enforcement of mask requirements in North Texas are turning their anger on workers, restaurants owners report.

Several Shell Shack locations have hired off-duty police officers to increase security on weekends because of recent altercations.

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“Customers are becoming so aggressive about this mask ordinance,” said Dallas Hale.

According to an executive order by the governor, restaurants in Texas must follow specific protocol to remain open. They are required, among other things, to mandate customers wear a mask from the moment they walk in the door until they are seated at a table.

Hale says he’s enforcing the rule.

“We don’t want to get shut down. Some of those places that don’t follow the rules have already been shut down and I have 500 employees who rely on us,” he said.

Hales says he buys boxes of masks to keep by the door of his restaurant to give away to anyone who forgets theirs. He offers patio seating and curbside pick-up, as well, to anyone who can’t wear a mask.

Still, he says, they get angry.

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“They’re flat out refusing. They start cursing. They’re getting loud. They’re making a scene in the restaurant. They’re telling me that we have to let me in,” said Hale.

At Love and War in Texas, a Plano restaurant, owner Cathi Maxwell says upset customers are lashing out at her teenage employees.

“They’re kids. They’re doing their jobs. They’re making 10 – 11 bucks an hour standing their sanitizing and opening doors. And that’s who they’re getting mad at it,” she said.

In one case, she said a customer, who was asked to leave, blasted her restaurant on Nextdoor.

“Love and War in Texas = Fascism!” he wrote. According to his post, the man told a manager he had a disability and couldn’t wear a mask. After the manager insisted, he walked outside to get a mask, but returned “with my hand over my mouth and nose”. The manger, he says, refused to seat him.

“It worked out well for us,” said Maxwell of the post. “He apparently within a couple days had gotten a hundred or so responses from his neighbors telling him we were doing the right thing.”

She says, the restaurant saw business increase, with several people noting they’d read about it on Nextdoor.

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The upset customer, Maxwell says, even called back to apologize.