The PSNI have said they are investigating an incident in which a 13-year-old was arrested, after footage purporting to be from the scene was posted on the internet.
A video circulating on Facebook shows a boy being grappled with by police, hitting the ground, and being detained there by two officers.
There appears to be blood on the ground and around the boy’s mouth.
At the same time an onlooker films the incident for two minutes, whilst a voice off camera shouts abuse at the officers.
At one point a voice says that their mother is a barrister, and will help the arrested boy out.
Sinn Fein’s John O’Dowd called the footage “deeply disturbing”.
The PSNI said they had responded to a report of an assault on a young male involving a number of youths in Solitude Park on Saturday.
They arrived at around 7pm and were directed to a large group of youths believed to have been involved, whom officers suspected had been drinking.
Police said the group were told they would be searched and “became aggressive and confrontational”.
They added: “A 13-year-old male was restrained and consequently arrested for assault on police, before being taken to his home address.
“Enquiries into the incident are ongoing and body worn video evidence of the incident will be reviewed.
“We are aware that a complaint has been made to the Police Ombudsman for Northern Ireland, and as such, it would be inappropriate to comment any further at this time.”