Swindon Town's head coach has condemned violence after the club's match against Port Vale last night, saying his players were "physically and verbally assaulted".
Players have also spoken out, claiming they were kicked and had bottles, coins and lighters thrown at them.
Hundreds of Port Vale supporters rushed onto the pitch after Swindon Town lost 6-5 in the League Two play-off final against Port Vale last night (19 May).
Footage then appears to show fans surrounding Swindon Town players before punches were thrown.
Right-back Mandela Egbo later tweeted a picture showing a cut to his nose, saying he had been attacked.
Striker Harry McKirdy also spoke out after the game.
Posting on Instagram, he said: "I'll take the stick and the songs - but bottles, coins, lighters thrown at me - running on and hitting me/teammates. [It's] too far - something's got to happen @EFL."
Speaking after the match, Swindon Town's head coach Ben Garner said: "Players have been physically and verbally abused. I've seen it in some of the other play-off games.
"I don't know where we're going as a country with this. It's absolutely disgusting."
He told ITV News he felt unsafe, describing the situation as "madness".
'It's madness' - Ben Garner speaks out on violence
He added: "In any other profession, you wouldn't put up with that abuse - so why are they having to put up with it?
"It's just madness. For me, anyone who has gone on that pitch, just ban them. They were told before the game 'if you come on the pitch you're banned' - follow through on it."
He claimed people did not go onto the pitch to celebrate but to "antagonise", adding: "I think something needs to be done before something serious happens."
Staffordshire Police say they are working with both clubs to investigate an assault on a player and identify those responsible.
Superintendent Gemma Ward said “Anyone seeking to ruin this will be firmly dealt with – such actions have no place in our local community. A thorough investigation in now underway.”
A spokesman for Port Vale FC said that the club 'will not tolerate such irresponsible behaviour' and it 'remains committed to taking the strongest possible action against anyone found guilty of being involved in criminal activities – including barring individuals from future games'.
EFL Security and Operations Advisor Bob Eastwood said, "Criminal behaviour at football is unacceptable and the EFL reiterates in the strongest possible terms that acts of disorder will be dealt with by the relevant authorities so that the game can be enjoyed by proper supporters.
"This should serve as a warning to others that football is committed to tackling and removing disorder from our game."
In a statement, the FA told ITV News West Country it is aware of the incident and will be looking into it.