A man in his thirties was attacked during an attempted robbery as he walked his dog in Chesham in the early hours of Tuesday morning.

At around 12.15am the victim was walking along an alleyway in Deansway when he was approached by four young men.

Thames Valley Police say the offenders asked the man to hand over his phone and - when he refused - started to punch him.

The victim managed to fight off the offenders, who ran off empty-handed towards Darvill Drive.

According to the police, all of the offenders were white and aged between about 16 and 18.

They were all wearing dark clothing and one wore a dark Adidas hooded top and Adidas baseball cap. One of the offenders was riding a pushbike, which was left behind at the scene.

Investigating Officer, PC Mark Turner, said: "This was a group of young men who may have been seen, or be known, in the local area. One of the offenders was riding a Grey/Black 'Topeka' dual suspension mountain bike which was left behind after they ran away from the scene."

Call Thames Valley Police on 101 with information or contact the independent charity Crimestoppers anonymously on 0800 555 111.