A police force is reviewing whether footage of its officers restraining a man who repeatedly shouts “I can’t breathe” needs to be investigated.

In a video circulating on social media, a man is lying on the ground, restrained by three officers, on a hill behind a police car in Brighton.

Sussex Police said the man was arrested and became aggressive towards officers before being placed on the ground.

Brighton and Hove policing commander Chief Superintendent Nick May said the force understood that some may find the video shocking but added that it showed a “small part” of a much longer interaction.

The incident has been referred to the Independent Office for Police Conduct (IOPC).

In the video, the man on the ground says: “Why have you got your arm on my neck?

“Bro, I can’t breathe.”

An officer replies, saying the arm is on the man’s collarbone, not his throat.

Speaking to the PA news agency, a woman who saw the man being taken to the ground said it was “intense”.

The witness, who wanted to remain anonymous, said she did not see what happened before that.

“I have seen people be arrested before, I have never seen anything like that,” she said.

“It was really, really shocking.

“I do not understand why there were three policemen sat on him.”

She recalled seeing the man “tackled” to the ground by the officers.

In a statement on Thursday evening, Mr May addressed the video of the Montpelier Road incident and another video which reportedly showed an incident in Hove last week.

On Friday, officers in Hove stopped a man who appeared to be concealing a blade. He was found in possession of a pair of garden shears and arrested.

A further search recovered two kitchen knives and suspected stolen goods, Mr May confirmed.

He continued: “We understand that some people may find these videos shocking but it is important for people to understand the wider context. Both videos show a small part of much longer interactions.

“All police officers are trained to use reasonable force, lawfully and proportionately, if they believe there is an imminent risk of physical harm to either the public or to themselves, and if they cannot otherwise defuse the situation.

“We are reviewing these incidents, including body worn video footage captured at the scene, to identify if any further investigation or learning is required.”

It is vital people can trust and have confidence in our policing approach, that we are fair, inclusive and that we treat everyone in our diverse communities equally and with respect

Mr May confirmed that the arrest of the man in Montpelier Road had been voluntarily referred to the IOPC for additional scrutiny.

He added: “It is vital people can trust and have confidence in our policing approach, that we are fair, inclusive and that we treat everyone in our diverse communities equally and with respect.

“We meet regularly with community groups and independent advisers to seek their feedback and advice on this but accept there is always more work to do.

“We await the outcome of the reviews of these incidents and will take any appropriate action as required.”

Both men remain were released under investigation, police said.

We are aware of this matter and are making further inquiries with Sussex Police

In a separate statement, Sussex Police said: “Police officers searching for a vulnerable missing teenager attended an address in Montpelier Road in Brighton at 10.15am on Tuesday 7 July.

“A resident of the address, a 28-year-old man, refused police entry and was arrested.

“Police subsequently found the missing 17-year-old young woman hiding at the property and returned them safely home.

“Once under arrest, the man became aggressive towards officers and was handcuffed and placed on the ground before being transported to custody.

“We train our officers to protect themselves and others using reasonable force and are reviewing this footage, together with body-worn video captured by the officers of the entire interaction, to identify if any further investigation or learning is required.”

A spokesman for the IOPC said: “We are aware of this matter and are making further inquiries with Sussex Police.

“We will then be in a position to make an informed decision on the level of IOPC involvement.”