Saturday’s meeting between the two clubs at The New Den was marred by home fans waving Turkish flags and shirts in the direction of United’s 2,191 travelling support.
Visiting fans were also subjected to chants of ‘Istanbul’ from a sizeable number of the sell-out crowd, while throat-cutting gestures were aimed at the Leeds contingent during Millwall’s 3-2 victory.
All three actions were sick references to the deaths of Christopher Loftus and Kevin Speight in the Turkish capital, the shameful scenes coming just four days after the 11th anniversary of the murders.
Millwall have since vowed to crack down on any supporters involved, with chief executive Andy Ambler claiming that four fans ejected during Saturday’s game have been banned indefinitely by the club.
Leeds assistant Snodin, said: “I didn’t know much about what happened while the game was going on. But, afterwards, I was told and it is not nice. For me, it is a horrible thing to do.
“I am an honest person and say what I think. It is not nice for all the families and our fans to have to remember. You don’t want to see that going on. People have died. No matter what the club is or what a rivalry is like, that sort of thing should be left alone.
“It is a positive move (to ban the offending supporters). No matter what the club is, Millwall or whoever, you just don’t want to see things like that. They kicked racism out of football, so why not this?”
The ‘Istanbul’ chants and waving of Turkish flags were not the only unsavoury incidents during the Championship encounter with home fans also holding up a banner reading ‘Sutcliffe 13-0’ – a reference to the Yorkshire Ripper killings of the late Seventies and early Eighties.
A bottle was also thrown at Kasper Schmeichel during the second half, and a deodorant can was launched onto the field from the main stand.
It was, though, the mocking of the murders of Mr Speight and Mr Loftus, which took place on the eve of a UEFA Cup semi-final against Galatasaray in 2000, that left Leeds supporters and officials fuming.
Millwall chief executive Ambler said: “As clubs, we have a responsibility for the behaviour of our own fans and take incidents such as this extremely seriously.
“We have already identified a number of people and will continue to work tirelessly, using all possible evidence, to identity and prosecute perpetrators.”
Similar scenes scarred last season’s meeting between the two clubs in the capital with one Lions fan even sporting a Galatasaray shirt and making stabbing gestures.
On the field, United’s defeat to Millwall allowed several of the chasing pack to make up ground on Simon Grayson’s men – leaving the Elland Road coaching staff to call for a positive reaction tonight at Derby County.
Snodin said: “For me, it is great to have a game so quickly. The great thing with this group of players is they don’t sulk. They just get on with the next one.
“The spirit is great. They have turned it round after a bad result a few times this season. That is the sign of a good group. Once you start losing two or three games in a row, it can quickly become four and five.”
On the threat posed by a chasing pack that is headed by Millwall, Snodin added: “We have been looking above us, not below. It is only when the gap is down to one point that you start looking behind you.
“I am sure the fans would have taken this position at the start of the season, six points behind second place and four points clear (of seventh).”
Derby go into tonight’s game also looking for a win to settle the nerves, Nigel Clough’s men being three places and eight points above the drop zone.
Snodin said: “Derby probably need it (one more win) as they will be still looking over their shoulders.
“After the first game when they came to Elland Road (and won 2-1), I expected them to do better than they have. Derby looked a decent football side.
“But since then, they have faltered a bit. They have a great crowd at home but, if it is not going right after half-an-hour, they do seem to get on their backs. Derby don’t seem to be able to handle it.
“They also have Robbie Savage in there. He has been a great pro but, hopefully, we can exploit him having ‘no legs’.”
George McCartney faces a fitness test this morning after missing the defeat to Millwall through injury as Leeds look to improve a defensive record that is the fifth worst in the Championship.
Snodin said: “We have been like that all season – great at scoring goals but leaking them at the other end. It does hurt that we haven’t kept more clean sheets.
“But, hopefully, we can sort that out in the next six games. It is baffling at times because, no matter what pairing or permutation we have had, we have still been leaking goals.”
Last six games: Derby County DLWDLD, Leeds United WWDLWL.
Last time: Derby County 2 Leeds United 1; November 11, 2008; League Cup.
Referee: S Tanner (Somerset).