ABC News(LANCASTER, Pa.) — Danene Sorace, the mayor of Lancaster, Pennsylvania, said an investigation is underway after a viral video on social media showed a Lancaster police officer tasing a black man in broad daylight.

“Like you, when I saw the video I was upset by it and it is of great concern to me,” Sorace said Friday in a video posted to her Facebook page. “We take the use of force very seriously. There is an investigation that has already commenced.”

She added that her team is already in contact with civil rights groups to address their concerns.

Blanding Watson, president of the Lancaster NAACP, told the Lancaster Online that the incident “requires a full investigation.”

On Thursday, Lancaster police responded to a 911 call that said a man was going after four people with a bat, according to authorities. Officer Shannon Mazzante responded to the call and told the man to sit but he did not listen, authorities said.

The man, who has been identified as Sean Williams, would not leave a woman alone and “kept repeating that he wanted a specific item, his Social Security card, from her,” police said.

Shortly after, a second officer responded to the scene. Officer Philip Bernot warned Williams that a Taser would be used if he did not listen, police said.

Bernot deployed the Taser and took Williams into custody. He was charged with a criminal warrant for possession controlled substance and public drunkenness.

Bystanders told police Williams “had been exhibiting increasing erratic behavior over the previous few days.” They did not mention that he was carrying a bat.

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