There are more police probes being launched into the events at the end of yesterday's Manchester derby.

The Daily Mail says a police investigation is under way into allegations that racist messages have been sent to the Manchester United defender's Twitter account, while one man was also arrested inside the stadium for racist chants aimed at another supporter.

United celebrated a titanic 3-2 win that put them six points clear at the top of the table and ended City's two-year unbeaten home run in the Barclays Premier League.

An FA spokesman said: "It is disappointing that after a great game and advert for the Premier League that we are discussing this issue.

"We will work with the clubs and authorities to identify those responsible and support the strongest sanctions available, including life bans.

"We condemn any such acts and it is simply unacceptable that any player is exposed to injury in this way. To witness Rio Ferdinand leaving the field with a cut above his eye to receive treatment is appalling.

"Football in this country has made great progress over recent decades. However, we must maintain the safety and security inside of our stadia and to do this we need to isolate and identify any individuals guilty of offences with strong penalties to act as a deterrent to others."