The UK's police watchdog on Friday said it had launched a criminal probe into an incident caught on video in which an officer appeared to kick and stamp on a man's head while making an arrest.

Greater Manchester Police in northwest England has suspended an officer from all duties following the incident at Manchester Airport on Tuesday.

"We can confirm we are conducting a criminal investigation into the use of force during events which took place on 23 July at Manchester Airport," said Catherine Bates, regional director of the Independent Office for Police Conduct (IOPC).

The officer involved would be formally interviewed "as soon as possible," she added.

The video, which has circulated online, caused public outrage and two nights of protests in Manchester and nearby Rochdale. The IOPC said it was looking at the "level of force" used.

Greater Manchester Police has said that three officers were assaulted, with one female officer "suffering a broken nose" and requiring hospital treatment, while apprehending a suspect at the airport following reports of an assault.

Details of what happened immediately before and after the video remain unclear. Police said the "use of such force in an arrest is an unusual occurrence and one that we understand creates alarm."

Mayor of Greater Manchester Andy Burnham said after seeing the full footage leading up to the circulated clip that it was "not a clearcut situation" and that while the clip was "disturbing," there were issues "on both sides."

Two men were arrested on Tuesday on suspicion of assault and assault of an emergency worker among other counts.

Two other men were arrested suspected of affray and assault of an emergency worker. (AFP)