Vision filmed on a mobile phone appears to show police officers push a drunk young man onto a busy city street, chase another to pepper spray him and smash one man’s phone during an ugly encounter in the Perth CBD on Sunday evening.

Four men aged 19 to 24 have been charged with disorderly conduct over the incident but they say they plan to fight the charges.

WA Police say they are investigating to determine if the force used during the arrests was excessive or justified.

One of the men who filmed the incident admitted yesterday he and his friends sparked the interaction with police by swearing and mouthing off while walking along Barrack Street after a night out at Elizabeth Quay.

But Ben complained that there was no justification for the police response. “That’s why I tried to film it,” he said.

Phone footage shows that as officers speak to one hand-cuffed man, their colleagues draw their Tasers and pepper spray and order the man’s friends to move away.

One officer pushes a man in the back and another teen appears to be walking away when a police officer follows him and pepper sprays him.

Another man claimed he had his phone ripped from his hand by one officer and thrown against a wall.