The incident happened at 9.10pm on Eastborough, when officers were responding to a report of a 17-year-old boy missing from home. The arrested boy remains in police custody at this time. It is believed there is some mobile phone footage of this incident circulating on social media. Officers investigating this incident ask anyone with any footage, or anyone who witnessed the incident, to get in touch. Dial 101, press 1 and pass information to the force control room, quoting reference number 12210194736.