New statistic show there has been a sharp rise in violent crimes and sex attacks on the London Underground network.
British Transport Police recorded 1,961 combined violent and sex crimes on the Tube and DLR in the first six months of the year.
That compares with 1,389 crimes for the first six months of 2015 - an increase of 41 per cent.
Most violent or sexual crimes were reported on the Central Line, which saw 314 such crimes overall between 1 January and 30 June.
The most violent incidents occurred on the Jubilee Line, with 241, while the Central Line saw the most sex offences with 88.
Authorities suggest that an increase in the number of people using the Tube (more than 11 million every day) will be a factor. BTP also said a rise in the number of sexual offences had been expected following the launch of 'report it to stop it' in April last year , which was a campaign to tackle sexual assaults on public transport.
According to the Metro, Chief Superintendent Martin Fry, BTP divisional commander for London, said: "It is disappointing see that after 11 years of reductions in crime that there was an increase last year.
Despite the increase in crime statistics, Steve Burton, TfL's Director of Enforcement and On-Street Operations, told the Evening Standard: "The Tube network is a safe, low-crime environment with very few people ever experiencing or witnessing crime.
"In the last 12 months there have been around two violence offences for every million passenger journeys and the vast majority of these were low-level with serious violence being thankfully rare."
However, he added: "One crime is one too many and we are working closely with the police to further improve the safety and security of travelling on our network."