Detectives investigating a string of robberies on trains across London have released CCTV images of three men they want to speak to after two 16-year-olds were attacked on a train between Upminster and Chafford Hundred.

The incident, on Thursday November 7 at around 8.30pm, saw the trio of would-be thugs attempt to rob the two children at knifepoint.

The group did not succeed in stealing anything from the two teenagers.

But today (Monday, November 18), the British Transport Police (BTP) have revealed the incident is part of a large spike in robberies on trains over the last two months.

CCTV images have also been released relating to similar robberies at White Hart Lane, Highbury and Islington, Lancaster Gate, Tottenham Court Road, Southbury, Euston and Seven Sisters.

The offences occurred between October 6 and November 9.

The BTP's Det Ch Insp Sarah White said: ""Recently we have seen a concerning amount of robberies across the rail network in London, and we are working tirelessly to catch those responsible.

"We have specialist plain clothes officers operating across the network, and passengers can also expect to see highly visible reassurance patrols across key routes and areas.

"However, I would still like to remind everyone of the need to be aware of their surroundings when travelling, particularly in the evenings, and of being discreet and secure when carrying their property where possible.

"Typically, we are seeing things like phones, laptops and Airpod earphones being targeted by groups of young men.

"They will usually approach people travelling on their own, but many of these incidents have still taken place in crowded and busy areas.

"Thankfully we police a CCTV rich environment which has enabled us to quickly identify a number of suspects and bring them into custody, and I'd now like to appeal for your help in identifying the men in these photos.

"Crucially, the travelling public are our eyes and ears and I would also ask that anyone who notices anything suspicious or that doesn't feel right to trust their instincts and text us discreetly on 61016, or to call 999 in an emergency.

"If you recognise any of the men in the CCTV images please text 61016 or call 0800 40 50 40 quoting 334 of 14/11/19."