A teenager needed hospital treatment after he was robbed by two men, one of whom was reportedly armed with a machete.

Police say the boy was assaulted and suffered two deep cuts to his skin during the incident which happened a month ago.

The robbery came to light after the Observer was tipped off this week about a serious incident which had been alleged to have occurred near Parmiter's School "in recent weeks".

Following enquiries, Hertfordshire Constabulary confirmed its officers are investigating a robbery which happened in Garston on May 11.

A police spokesperson said: "Detectives are investigating a robbery which happened on the afternoon of Tuesday 11 May.

"The victim, a teenage boy, was walking in the alleyway between High Elms Lane and Boundary Way when he was approached by two men.

"One of them brandished a machete and assaulted the victim, who dropped his rucksack and managed to run away.

"A later search of the area did not locate the bag so it is believed the offenders stole it.

"The victim suffered two lacerations which required hospital treatment."

No description of the suspects have been given but police say enquiries by the local crime unit are ongoing.

There have been no arrests made in connection with the incident.

Anyone with information should contact police quoting 41/34381/21 or contact Crimestoppers anonymously on 0800 555 111.