The initiative aims to reduce robberies on the Tube

The 15-day initiative involves 300 police officers from British Transport Police, the Met Police, City of London Police, and Surrey Police.

High profile patrols and drugs sniffer dogs are among the tactics being used in the crackdown.

The aim is to reduce, disrupt, and detect robberies on the rail system, Tube, and the Croydon Tramlink.

'Loutish behaviour'

The initiative - named Operation Hastings - began on Monday and has been set up as part of the Government's Street Crime initiative.

British Transport Police Dep Ch Con Andy Trotter said: "Robberies are a real problem for London. They are very much part of the yob culture which causes many passengers stress and anxiety.

"There is a spectrum of anti-social behaviour that extends from alcohol-fuelled loutish behaviour through to robberies and assaults on rail staff and passengers."

A special control room and dedicated London-wide intelligence gathering operation covering all forces has also been set up.