The Football Association (FA) has condemned pitch-invading fans after a number of high-profile incidents of violence near the end of the English league season.
Earlier on Friday, Merseyside Police announced they had launched an investigation into an altercation between Crystal Palace manager Patrick Vieira and a fan, after Everton supporters flooded onto the Goodison Park pitch to celebrate the Toffees securing Premier League safety with a 3-2 comeback victory.
Widely circulated footage appeared to show Vieira kicking out at the fan after being goaded, while this week also saw a Nottingham Forest supporter jailed and given a stadium ban after attacking Sheffield United player Billy Sharp following a Championship play-off semi-final at the City Ground.
Elsewhere, Swindon Town players were allegedly physically and verbally abused during a pitch invasion at Port Vale, while a Northampton Town fan appeared to shove a Mansfield Town player during League Two's other play-off semi-final tie.
English football's governing body has now moved to condemn the scenes and confirmed it is investigating each of the pitch invasions to have taken place over recent days.
"We are very concerned about the rise in anti-social behaviour from fans as we reach the end of the season," a statement from the FA began.
"Football stadiums should always be a safe and enjoyable space for everyone, and these incidents are completely unacceptable and have no place in our game.
"It is illegal to enter the pitch area in any stadium and these actions are putting players, fans and people who run the game at great risk. This simply cannot continue, and we can confirm that we are investigating all of the incidences.
"Clubs play a vital role in addressing this issue and they need to prevent pitch invasions from occurring, as well as taking their own action against those that break the rules and the law.
"The FA will be seeking to do all that it can to work with clubs as well as addressing the issues from a disciplinary perspective. We are also reviewing our regulations to help stamp this behaviour out and to ensure the safety of everyone inside a stadium."