West Ham 2-2 Man Utd: Robin van Persie was offside - Sam Allardyce

West Ham boss Sam Allardyce says Robin van Persie's equaliser for Manchester United was "blatantly offside" after they twice lost the lead to draw 2-2 at home.

Van Persie turned in United's second in the 77th minute, although replays showed the Dutchman was in an offside position.

Allardcye says he is "bitterly disappointed" to be deprived of what would have been a "famous victory" over the league leaders.