The FA is looking into incidents of disorder at Preston's 1-0 win over Blackpool in the Capital One Cup, after which a steward was trampled by a police horse as home fans invaded the Deepdale pitch.

The steward, wearing a hi-visibility jacket, was struck by a horse as it cantered across the pitch, while another horse – also helping with crowd dispersal – appeared to step on the man as he lay on the ground.

An FA spokesman said: "We will be looking into what happened, including liaising with both clubs and the police to get a full picture of events and what preparations were in place."

The fans were criticised by the police, with the match commander chief inspector Nick Emmett saying: "The behaviour of those involved in the disorder and the behaviour of some people towards officers and stewards was absolutely disgraceful.

"This was a very difficult situation which presented significant challenges for both the club and for ourselves and we were able to bring the situation under control quickly. The disorder last night was completely unacceptable and we will be making significant efforts to locate and prosecute those involved."

Blackpool's manager Paul Ince labelled the scenes an "absolute joke" and added: "I understand that fans get excited … but who knows what can happen? We're not listening. Has someone got to be stabbed before we listen?"

He added: "I wondered if we have enough stewards. You see enough situations where fans run on a pitch and I can understand fans' excitement, but there have been enough frightening things that have happened to players that we need to stamp down on it.

"There were three or four hundred Preston fans, so who knows what could have happened? Has it got to take something else to happen before we listen? That's not just Preston but it's the whole football community in general. We need to knuckle down on this.

"We're disappointed as our fans were absolutely fantastic and their behaviour was impeccable. There were no louts on the pitch – unlike Preston – and we conducted ourselves in the right manner. We have to take pride from that as a club."

Police said two people were arrested for criminal damage to one of the supporters' coaches outside the ground, with another four held for minor offences.

Preston issued a statement on Tuesday that said: "Last night's cup tie was attended by 17,470 fans, some 4,400 from our visitors Blackpool.

"Given the historic rivalry between the two clubs we ensured that our ground safety pre-match planning considered all aspects of potential crowd issues to ensure that all supporters could attend the match in a safe environment. This pre-planning included a significant increase in stewarding and also appropriate police presence both inside and outside the stadium.

"At the final whistle a number of supporters [approximately 200] ran on to the pitch in celebration at the result.

"This incursion on to the field of play is totally unacceptable and is condemned by everyone connected with Preston North End.

"The measures that had been put in place in anticipation of such an event worked as planned and at no time were rival fans in contact with each other and the pitch was cleared as quickly as possible.

"Contrary to early press reports, the steward that was seen on TV in contact with a police horse was not taken to hospital and went home with colleagues after being given the all-clear by medical staff at the ground. The only steward to receive any injuries at the stadium was working in a part of the stadium occupied by the visiting supporters.

"In reiterating that any invasion of the pitch is unacceptable, we would like to commend the police and stewards for responding in a timely and appropriate manner."