Four teenagers have been robbed at knife-point on a train.

A distraught mother has revealed on Facebook how her son and three friends boarded a train at Otford yesterday lunch time to travel to Swanley.

They were followed onto the train by four older youths.

Once under way, the second group demanded to know what they had in their bags, saying they had knives.

One boy handed over his bag, and the woman's son was forced to hand over his Moncler jacket.

Three of the boys were allowed to get off at Shoreham, but her son, who refused to hand over his bag and phone, was kept back on the train and told he would be stabbed.

He was eventually allowed to get off at Eynsford.

The boys called 999 and two suspects were arrested at Bickley Station and taken into police custody, the woman said.

The older group is described as black and aged around 17-19.

The mum said: "Fortunately all the boys are okay. It could have been a lot worse. But people need to be aware that this sort of thing is happening."

British Transport Police has been contacted for comment.

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