Hull have condemned the "mindless hooliganism" which marred Saturday's 2-0 FA Cup victory over Millwall and accused visiting supporters of attending the match "with the single intention of causing maximum disruption".
Police in riot gear quickly joined stewards to deal with the trouble which first broke out before the kick-off in a corner of the North Stand where the away fans were closest to Hull supporters in the East Stand.
In the second half, a further incident was spotted in the other corner of the North Stand which was packed with Millwall supporters who had made the trip north. Twelve people were arrested.
Tigers chairman Paul Duffen said: "There is no place for this kind of mindless hooliganism in football. It is an ugly throwback to a bygone era which most clubs have long since eradicated from their culture.
"Hull City Football Club will be seeking full financial compensation from Millwall for all the damage and will be making the strongest representations to the football authorities regarding this incident."
A statement on club website this morning: "Hull City AFC utterly condemns the violence and criminal damage caused by Millwall supporters at the Kingston Communications Stadium during yesterday's FA Cup fourth round tie.
"A full statement will be issued on conclusion of police and stadium investigations, but it is already clear that a significant contingent of the travelling Millwall supporters arrived at the match with the single intention of causing maximum disruption.
"Over 50 seats were destroyed together with toilet facilities and concession shutters, all in the North Stand occupied by visiting supporters."