Spanish police said Thursday they had opened a disciplinary inquiry after a hit YouTube video seemed to show an officer striking a girl during protests against Pope Benedict XVI's visit to Madrid.
"The police directorate has requested that a disclipinary inquiry be opened into three officers," a national police spokesman said.
"There is the video and other elements. The inquiry will cover the whole incident."
The widely viewed YouTube video purports to show police actions on August 18 during an unauthorized protest in Madrid over the cost of the pope's August 18-21 visit for World Youth Day festivities.
In the video, at least eight officers in riot helmets can be seen crossing a road in central Madrid.
From behind, one officer can be seen throwing his arm towards the girl's face as if he is punching or slapping her.
She recoils as if struck although the angle of the shot obscures the moment of contact.
As a male friend drags the girl away, at least one policeman can be seen striking him from behind with a baton.
A few moments later, an officer can be seen swinging at a man in a white t-shirt -- later identified by Spanish media as a photojournalist -- standing on the pavement nearby.
The man is left rolling on the ground as riot police walk away.
The girl apparently attacked by the riot police was identified in Spanish media as a 17-year-old whose first name is Katerina.
She was quoted by leading daily El Pais as saying she had shouted insults at the riot police, calling them violent, before they struck her on the face and hip.
The video created an uproar online. A Facebook page launched after the incident, titled "Identify and expose the policeman who assaulted the young girl," attracted more than 16,800 fans.