An investigation has been launched after four people were arrested following an attempted robbery at a bakery in Houghton-le-Spring, Sunderlandbr Police received a report of a robbery at Edinburgh Bakery on Station Avenue North, Fencehouses at 9.25am on Monday, October 31.br br It was reported that an offender entered the store and made threats towards staff, demanding money from the till, but made off empty-handed a short time later.br br Officers were deployed to the area and an investigation was launched.