An altercation occurred between a man and a group of men on Pier Approach near to Bournemouth Pier at around 7pm on Saturday 12 June.

It is reported the victim – a 19-year-old man from Fareham – was hit, causing him to fall to the ground and hit his head.

He was taken to hospital with a serious head injury and his condition is described as stable.

A 17-year-old boy from Blandford was arrested on suspicion of grievous bodily harm and is assisting officers with their enquiries.

Detective Sergeant Ian Allen, of Bournemouth CID, said: “From our initial enquiries we are aware that there were a number of people on the beach at the time and some appeared to be recording the incident on their mobile phones.

“I would ask anyone who witnessed the incident, or captured it on their mobile phones, to please contact Dorset Police.”

Anyone with information is asked to contact Dorset Police at www.dorset.police.uk, via email 101@dorset.pnn.police.uk or by calling 101, quoting occurrence number 55210093654. Alternatively, to stay 100 per cent anonymous, contact the independent charity Crimestoppers online at Crimestoppers-uk.org or call freephone 0800 555 111.