Police officer caught on camera brutally punching woman in the face (GRAPHIC VIDEO)

An Arizona police officer has been placed on administrative leave after shocking video footage of him violently punching a woman in the face emerged online.

The graphic video shows two police officers attempting to arrest the woman outside a house in the city of Flagstaff. The woman repeatedly asks why she is being arrested and if there is a warrant out against her. She also requests a lawyer.

The police officer, who has been named as Jeff Bonar, appears to lose patience with the woman and he hits her in the face with a powerful punch.

This sparks an angry reaction from all those present including the man filming the incident, Danny Paredes, who shouts “Hey! You can’t hit a girl like that!”

Paredes later uploaded the video to Facebook and it has been shared thousands of times since Wednesday. “It was just shocking,” he told the Arizona Republic. “I pulled out my camera immediately.”

On Wednesday Sgt. Cory Runge of the Flagstaff Police Department said in a statement that they became aware of the video on Wednesday evening.

"Our agency is very concerned by what is depicted in this video," Runge said. "We are immediately initiating an internal investigation into this incident."

The Arizona Republic is reporting that the police were overseeing an eviction at the house where the woman was living when they seized her, mistakenly believing that there was a warrant out for her arrest.

“She had a warrant a few weeks ago,” the woman’s boyfriend, Jimmy Sedillo, said. “He still assumed she had a warrant.”

Sedillo, who is Paredes’ brother in law, said he and his mother, niece, brother-in-law and young children all witnessed the incident.

He later posted a message on Facebook thanking people for their support after the disturbing video went viral.