The act was believed to have been carried out by a group of teenagers who used ropes to bring the 2-ton statue down, The Times of London reported. The head was found in another part of the park.
"This is simply mindless vandalism," said Chris Burnham, a neighborhood inspector with the Merseyside Police. "It's a despicable attack on a historic statue."
Tom Brady of the Royal British Legion said the vandals' act "dishonors" the young soldiers being killed in Afghanistan.
In London, Queen Elizabeth II, Edward's great-granddaughter, unveiled a statue of Queen Elizabeth I at Westminster School. The statue was placed there as part of the celebration of the 450th anniversary of Westminster Abbey's Royal Charter.
The queen, accompanied by Prince Philip, also attended a service at the Abbey and opened a new education center at the school where a group of children performed Elizabethan dances.
Elizabeth also examined a chair she and her predecessors get to sit in once -- the coronation seat.