FA Cup: Fans arrested after Millwall violence
Police arrested 14 people during Saturday's FA Cup semi-final at Wembley Stadium which was marred by Millwall fans fighting each other during their club's 2-0 defeat by Wigan Athletic.
Some supporters were left bloodied while younger fans were left in tears.
Millwall FC said it could not "allow the actions of a mindless minority" to undermine the club's efforts to lose its reputation for hooliganism.
The Football Association said it deplored the "unacceptable" scenes.
The fans were arrested for offences including affray, possession of an offensive weapon, Class A drug possession, ticket touting and assault on police.
Twelve were Millwall fans while two were Wigan supporters.
The BBC's chief football writer Phil McNulty said the violence - the first significant trouble at the new Wembley stadium since it opened in 2007 - took place in the closing stages in several areas of Millwall's allocated end.
He said it was a shameful day for Millwall, whose fans made up about 32,000 of the crowd of 62,335, as an increasingly tense atmosphere built up throughout the second half before trouble flared.
Police and stewards moved in to try to stem the violence - witnessed by millions on TV - but it took some time to restore a measure of control.
Millwall chief executive Andy Ambler said in a statement: "Our position is clear - anyone associated with our club found guilty of violent behaviour will be banned indefinitely from Millwall matches in addition to any punishment they receive from the authorities."
He added: "At this stage we are still in the process of establishing the full details of what happened in a section of the ground during the second half.
"When we have those facts at our disposal and the police have completed their investigations we may be in a position to comment further."
Millwall manager Kenny Jackett said he had not been aware of "any fighting".
"I promise you, I wasn't aware of it during the game," he said in a post-match interview.
Told that children were carried crying out of the stadium, he said: "I am very sorry if that is the case."
Club captain Danny Shittu said it was "sad to hear about these things happening on a day like today".
'Very poor reputation'
"Things like that shouldn't be going on - it should be a great day for both sides."
FA general secretary Alex Horne said: "We will look to ensure those involved are identified and we would call for criminal charges and a football banning order to be brought against them."
Wigan Athletic chairman Dave Whelan told BBC Radio 5 live he understood why Millwall fans "want to fall out with the visiting team, but why would they fall out amongst themselves?".
"It just gives football a very, very poor reputation.
"We know Millwall are a tough club, their team's tough to play.
"But don't fight each other. I couldn't understand that."