POTENTIAL witnesses to a robbery in a Kent park are being urged to come forward by police.

The victims, a man and a woman aged around 20, pleaded with people on the grass area close to Gordon Promenade, Gravesend - known locally as Fort Gardens - to help them as they were forced to hand over cash and a mobile phone to another man.

The offender tried to snatch the young man's bag before grabbing the woman's collar and threatening to punch her.

The couple almost managed to get away when other people in the park approached, but the robber came up to them again and threatened the man with a rock and made him hand over around £35 and his phone.

Police are keen to speak to anyone who was in the park at the time of the robbery: about 8.30pm on Sunday.

The offender was seen talking to a boy of about 12 just before the incident.

PC Gary Cook, who is leading the investigation, said: "We know that the couple made pleas to people in the area to help them and we would urge them, and the young boy, to come forward.

"We would particularly like to speak to two men who were in the park together at that time and another three who were sitting on a nearby bench."

The offender is described as white, 5ft 9in to 6ft tall and in his early 20s. He had bushy eyebrows and wore a dark hooded top with a white motif and dark jogging bottoms.

Anyone with information is asked to contact police on 01474 565083 or Kent Crimestoppers on 0800 555111.