Police are appealing for help to find two men who robbed a teenager at knifepoint.

The 18-year-old victim was on a footpath in Spa Road, Witham, when the suspects took out a knife and demanded his Samsung Galaxy S5 mobile phone at about 4.45pm on Friday, February 27.

After taking the phone and his blue Carrera mountain bike, both fled the scene, one on the victim’s bike and the other on a black mountain bike.

The victim, from the Witham area, returned home and attempted to look for the suspects with his grandmother, who saw them with the bike near Asda in Highfields Road at about 5.15pm. When she challenged them they pushed her off her mobility scooter and ran away.

Dc Shelley Tarling, of Braintree CID, said: “This was a frightening incident for the teenage victim and the subsequent assault against his disabled grandmother is particularly appalling and cowardly.

“We would appeal for anyone who knows who is responsible to come forward.”

The first suspect is described as a white male, aged 16-20 and about 5ft 9in. He was riding the victim’s bike and wore a black tracksuit.

The second suspect is described as a white male, aged 16-20, about 5ft 9in tall and rode a black mountain bike.

Anyone with information is asked to contact Dc Shelley Tarling at Braintree CID on 101.