Police dogs and a helicopter were deployed following an altercation between a group of people in the early hours of Saturday morning.

Officers arrived at the scene in Lower High Street, Watford, just after 4am. There it was alleged that a watch and a bag containing a mobile phone had been stolen.

A search of the area was carried out with assistance from the police helicopter, dog unit and British Transport Police.

Two people were arrested a short time later.

An 18-year-old man was arrested on suspicion of robbery and has been released under investigation pending further enquiries.

A 17-year-old boy was also arrested on suspicion of robbery and subsequently charged with possession of a controlled drug (cannabis). He has been bailed to appear before youth court on August 2.