THREE school boys were robbed at knifepoint on a c2c train.

British Transport Police (BTP) detectives have released these CCTV images of three teenagers they want to speak to in connection with the robbery on a London-bound train.

The victims, aged 16, boarded the train at Leigh and were planning to spend the day at Lakeside shopping centre. During the journey, three young thugs approached them and threatened them.

In a sinister move, the thugs then followed the group off the train and forced one of the victims to withdraw more money from a cash point inside the shopping centre.

Det Con Jon Howlett, the investigating officer, said: "The three victims boarded a train at around 12.30pm heading towards Chafford Hundred station.

"Three teenagers approached the victims and threatened to stab them if they didn’t hand over money."

During the journey, the three boys said they had a knife and the victims saw the robbers passing around a shiny, metal object.

Det Con Jon Howlett added: "Fearing for their safety, one of the victims handed the suspect £20 from his pocket. As the train arrived at Chafford Hundred, the victims made their way towards Lakeside Shopping Centre but were followed by them.

"Once inside the complex, the boys approached the victims again and ordered them to withdraw money from a cash point. One of the victims then drew out £20 and handed in to the boys, who then made off from the centre."

BTP officers are viewing CCTV from the station, shopping centre and speaking witnesses who may have been on the train or at Lakeside that day.

CCTV images released to the Echo by the BTP show the three teenagers suspected of carrying out the robbery on Saturday, July 27.

One of the suspects is believed to speak with a strong Irish accent.

DC Howlett added: "Threats of violence and carrying offensive weapons such as knives is simply not tolerated by BTP. Luckily, it’s rare that people are faced with this type of threatening and fearful experience on trains, but, when it does occur, we do all we can to identify those responsible and bring them to justice.

"I’d urge anyone who has any information to come forward and assist officers in this investigation."

Anyone with information can contact British Transport Police on 0800 40 50 40 quoting background reference B11/LNA of 08/08/2013. Information can also be passed to the independent charity Crimestoppers, anonymously, on 0800 555 111.