A man in his 20s was cycling in the area of Wimborne Road and Talbot Road at approximately 3am on Tuesday 1 November when he heard someone running behind him.

The victim, who was wearing fancy dress, was subsequently assaulted and knocked off his bike.

He sustained a broken jaw and is receiving medical treatment.

Detective Constable Rachel Walker-Hatch, of Bournemouth CID, said: “This incident has left the victim seriously injured and we are carrying out enquiries to identify who is responsible.

“I would urge anyone who may have witnessed what happened to please come forward.

“Also, I am keen to speak to any residents who have CCTV or motorists travelling in the area with a dashcam to contact Dorset Police with any relevant footage to assist my investigation.”

Anyone with information is asked to contact Dorset Police at www.dorset.police.uk/contact or by calling 101, quoting occurrence number 55220177453. Alternatively, independent charity Crimestoppers can be contacted anonymously online at Crimestoppers-uk.org or by calling Freephone 0800 555 111.