Merseyside Police review video of an officer punching a teenage boy three times while gripping handcuffs in Speke

Merseyside Police launched a Professional Standards Department review after footage circulating on social media — viewed more than 40,000 times — showed the officer striking a handcuffed boy in the stomach, chest and throat during a Friday night callout in Liverpool.

Officers had been sent to Alder Wood Avenue after around 20 youths blocked roads with wheelie bins and aimed fireworks at anyone who tried to move them.

Youths had also reportedly smashed flat windows, attempted to start fires and threatened members of the public on what Liverpudlians call 'Mischief Night', the evening before Halloween.

Merseyside Police urged the public 'not to speculate and avoid sharing rumours' while insisting 'a short clip doesn't always show the full context'.