A football steward reportedly required hospital treatment after being trampled by a police horse during a pitch invasion.
The steward, wearing a hi-vis jacket, was on the Deepdale pitch helping clear fans after Preston North End's late winner against Blackpool at the end of the Capital One Cup game last night.
He was struck by a police horse as it cantered across the pitch, while another horse - also helping with crowd dispersal - seemed to clip the steward as he lay on the ground.
The BBC reported the man was taken to hospital with a suspected broken shoulder.
A Preston spokesman told BBC Sport: "A steward was injured by a police horse.
"He suffered damage to his shoulder, and has gone for an X-ray."
Police said two people were arrested for criminal damage to one of the supporters' coaches outside the ground, with another four people held for minor offences.
Superintendent Richard Morgan said: "Due to the match being a local derby, we had additional resources in place and as a result we were able to quickly respond to the pitch invasion that occurred at the end of the match to disperse the crowds and to bring back order.
"We are aware that a steward was injured inside the ground and I would like to reassure people that will be looking into the circumstances around how and why that happened.
"We have been working closely with the football club in the lead up to and throughout the match. I would like to stress that it is only a minority who have been involved in the disorder with the majority of supporters enjoying the event and getting home safely."
Tom Clarke headed the only goal as the League One side defeated Lancashire rivals Blackpool from the Championship.
John McDougall, who was reporting from the match for the Press Association, said: "It was a feisty game - not a dirty one - and there was clearly local pride at stake.
"At the end of the game there was a pitch invasion and some of the Preston fans went over towards the Blackpool supporters in the away end.
"Police, both on foot and mounted, formed a wall between the two sets of fans. It took about five or 10 minutes for them to clear the supporters.
"Both managers have condemned the pitch invasion."