Three teenage boys were told to hand over their valuables by two moped riders armed with a knife.

It was just after 1am on Saturday, outside the Alfred Arms pub in Shenley Road, Borehamwood, when a moped pulled up at a bus stop.

The driver, dressed in a grey tracksuit, and a passenger, wearing a balaclava, told the boys to give their things over, threatening them with a small knife.

A mobile phone was handed over before the boys ran off, Hertfordshire Constabulary said.

None of the victims were injured.

The moped driver was last seen riding towards Tesco and the second robber made off on foot in the same direction.

Police were called and carried out a search of the area but no suspects were found.

The driver is described as wearing a grey tracksuit and the passenger is described as mixed race with light skin and was wearing all black clothing with the hood up and a balaclava.

Police believe those involved know each other.

Any witnesses or anyone with information is asked to contact Hertfordshire Constabulary on 101, quoting crime reference 41/49154/19.