An image captured on video shows the police conduct under review.
CNN  — 

Police in Washington state are investigating an incident captured on video in which an officer can be seen kicking a teenager in the back Sunday during the Central Washington State Fair in Yakima.

The “use of force review” opened after city police officials learned of their officer “using force while effecting an arrest,” Yakima Interim Chief of Police Gary Jones said Monday in a statement.

The video, posted to Facebook by an apparent bystander, seems to show the officer trying to break up a fight as several people can be seen running in the background. About 15 people were involved in a fight, and police say four teens were arrested, local news media have reported.

“Police officers are often faced with difficult situations that require immediate assessment of circumstances in order to protect the community and themselves,” Jones said, promising to investigate in “an objective, meticulous manner that requires layers of oversight.”

The teen’s attorney called the officer’s conduct “abusive and unacceptable” and said the boy’s family “wants justice.”

“They need to know that they are heard, and they need to know that this type of conduct is wrong and they need to know that this is going to stop,” Bill Pickett told the Yakima Herald-Republic.

The Yakima Police Officers Association did not immediately respond to CNN’s request for comment.