Police responded to calls from residents who heard gun fire in Macbeth Close and arrived at the scene at about 5.20pm. A spokesman for Cambridgeshire police said: Officers attended an address in Macbeth Close and spoke to the occupants who said they had been threatened with a gun by a group of around four or five men. One of the occupants escaped by jumping from an upstairs window and two further occupants barricaded themselves in their rooms. The spokesman said that a bicycle and a mobile phone were stolen during the incident. Police believe that this was an isolated incident and an investigation is under way, added the spokesman. Anyone with information should call police on 101 or Crimestoppers, anonymously, on 0800 555 111 or through their anonymous online form at www.crimestoppers-uk.org.