A British police officer is under criminal investigation following an incident at Manchester Airport, where a suspect was kicked and stepped on during an arrest, according to the police oversight agency.

“We can confirm that we are conducting a criminal investigation regarding the use of force during the events that took place on July 23 at Manchester Airport. We are planning to interview a police officer under criminal protective measures as soon as possible,” said Catherine Bates, regional director of the Independent Office for Police Conduct (IOPC), in a statement on Friday. The involved officer will be formally interviewed “as soon as possible,” she added.

Greater Manchester Police has suspended an officer from all duties following the incident, which occurred on Tuesday. Video footage of the incident, which has circulated online, has sparked public outrage and led to two nights of protests in Manchester and neighboring Rochdale.

The IOPC is investigating the “level of force” used during the arrest. However, it remains unclear what transpired before and after the recorded incident. The police stated that “the use of such force in an arrest is an unusual occurrence, and we understand that it causes outrage.”

Greater Manchester Police reported that three officers were attacked while attempting to apprehend a suspect at the airport after reports of an assault. One female officer suffered a broken nose and required hospital treatment.

Andy Burnham, the Mayor of Greater Manchester, commented to the BBC after watching the full footage leading up to the circulated clip, stating that it was not a “one-off situation,” and while the clip was “disturbing,” there were issues “on both sides.”

Two men were arrested on Tuesday on suspicion of assault and assaulting a paramedic. Additionally, two other men were arrested, suspected of fighting and assaulting a paramedic.