Leeds and Chelsea fans warned by police

Behave, or else! Leeds and Chelsea fans issued warning before bitter cup clash | UPDATED: 22:28 GMT, 18 December 2012 Leeds and Chelsea supporters have been warned not to add another chapter to football’s season of shame on Wednesday night. The clubs go head to head in a potentially explosive Capital One Cup quarter-final at Elland Road. The two sets of fans have a long-running feud that stems back to the 1960s and, in a season already blighted by numerous off-the-field flashpoints, supporters have been told to behave themselves or face serious action.