ESSEX Police are appealing for witnesses after an 18-year-old man was robbed of his mobile phone while at a bus stop in London Road, Stanford-le-Hope between 7.15pm and 7.45pm on Friday, October 21.Four men and two women assaulted the victim causing concussion, facial bruising and cuts to his knees.Anyone who witnessed the incident is asked to contact Pc Owen Clements at Grays CID on 101 or Crimestoppers on 0800 555 111.