Arizona police say an officer is being investigated after video surfaced that shows him striking a woman in the face during an arrest.
Flagstaff police say in a news release that officer Jeff Bonar has been placed on leave pending the probe.
They say "our agency is very concerned by what is depicted in this video."
Police say the incident occurred Wednesday as police arrested a "somewhat uncooperative" woman.
Video apparently shot by an onlooker and posted on Facebook shows her struggling with two officers.
At one point one of men strikes or punches her in the mouth area. She is eventually placed in a squad car.
There was no word on what prompted the arrest, but Arizona Republic reports it spoke with a man who identified the woman as his girlfriend and that police indicated she faced an arrest warrant.