Local police have demanded Manchester United and Manchester City players do nothing that could incite the crowd at Wednesday's potentially explosive Carling Cup semi-final tie at Old Trafford.

Carlos Tevez and Gary Neville became involved in an ugly touchline spat, while police confiscated golf balls and darts from some fans, smuggled in as offensive weapons.

Assistant chief constable Ian Hopkins, of Greater Manchester Police, said: "I met with both clubs prior to the first leg and will be doing so again.

"We'll discuss the general crowd behaviour and making sure they [the clubs and players] understand their responsibility not to do anything that is likely to incite the crowd.

"It is going to be a very passionate game on Wednesday. There is a lot at stake for both teams and the fans."