Tuesday 19 September 2017 20:26, UK
Sheffield United's board have condemned the trouble that flared at the 1-0 home defeat to Norwich on Saturday.
A Blades statement revealed that incidents during and after the game had resulted in supporters being injured, objects being thrown on the pitch and "high-profile Norwich officials threatened and abused".
The South Yorkshire club have been reported to the Football Association following the Sky Bet Championship match and could face sanctions, including financial penalties.
The club, who face Sheffield Wednesday at Hillsborough on Sunday, live on Sky Sports Football, have banned seven individuals this season, including two from Saturday's fixture.
Frustrated Blades boss Chris Wilder was sent to the Bramall Lane stands after lashing out at water bottles during the defeat.
There was also trouble involving United supporters at the match away against Middlesbrough last month.
Tuesday's statement featured a message from the board, which said: "We simply will not tolerate the unsportsmanlike and illegal conduct of a few to spoil things for the large majority who come along to simply watch and enjoy a football game on a Saturday afternoon.
"At Bramall Lane, family values are paramount. Violence in any form is unacceptable at Bramall Lane.
"The club invests significant sums and management time in assuring the safety of our fans and guests and we shall redouble our efforts.
"We'd like to assure our fans and supporters that the staff and management of Sheffield United, in co-operation with South Yorkshire Police, will make every effort to assure a safe environment for the derby at the weekend.
"We are working with the police in coordinating a root and branch approach to identify those supporters who are tarnishing the name of Sheffield United and putting football in a very poor light.
"We want this element removed from our support so if that means other fans reporting incidents of unacceptable behaviour then let us know.
"We will issue life bans and impose other tough measures to deal with these fans."
The statement added that Sheffield United are "continuing to work with Cleveland Police following the August fixture at Middlesbrough".
