Almost half the robberies in Solihull are taking place on buses and two thirds of the robbery victims are teenagers.

Weapons and threats of violence are being used to force people to hand over money and property, most often mobile phones.

A police team set up to target the criminals has made nine arrests in the last two weeks.

Threats used

As well as catching the criminals, plainclothes police are giving passengers advice and showing them how to put security markings on their mobile phones.

Sergeant Kris Starynskyj, of West Midlands police, acknowledged that threats were often used.

He said: "A lot of the problems we have had have been gangs of youths approaching individuals or youths in pairs and bullying them with threats and occasionally weapons and then stealing property from them."

The police and bus companies are working together and many new buses have CCTV installed to deter criminals or provide crucial evidence if a case comes to court.

Many teenagers report being threatened by gangs, with mobile phones being the main focus of the thefts.

West Midlands police hope the new initiative will deter the criminal groups who until now have seen the buses as an easy hunting ground.