West Ham’s Europa Conference League semi-final win over AZ Alkmaar descended into utter carnage last night when several players dove into the stands to protect their families from thuggish Dutch supporters.

A horde of violent Alkmaar fans, clad in all-black and hooded to hide their identities, forced their way into the away stands to trade blows with West Ham supporters at the final whistle. The scrap quickly spiralled out of control as dozens of hooded hooligans flooded into the section holding the family and friends of West Ham’s victorious players.

Without hesitation, West Ham’s Michail Antonio and Flynn Downes leapt over the hoardings and made a beeline for the stands, closely followed by team-mates Lucas Paqueta and Said Benrahma.

Shocking footage from the stands saw brave West Ham supporters desperately trying to hold back the stream of Alkmaar ultras from attacking the families, while others stood atop a stairwell duking it out blow-for-blow with the oncoming horde. 

Just as it looked as though the violence was set to descend into an all-out brawl, security teams managed to force their way into the melee and separate the crews, with other guards jumping in to hold back the furious West Ham players.

Meanwhile, one elderly West Ham fan known as “Knollsy” received plaudits on social media for springing to the defence of West Ham defender Thilo Kerher’s girlfriend. One West Ham supporter who witnessed the scrap posted an emotional message of thanks and support to Knollsy.

“A bit of context: we were sitting behind Thilo Kerher’s girlfriend. Knollsy was worried about her and walked to the top of the stairwell, fending off the storming Alkmaar fans. He’s a lovely bloke and did what he felt was right at the time. He stopped those fans.”

The message received a stream of support from other social media users who applauded Knollys’s actions.

Order was eventually restored and David Moyes” side could head over to the away end to toast their 3-1 aggregate win, sealed by Pablo Formals” injury-time winner which fired West Ham into next month’s Europa Conference League final.

West Ham goalkeeper Alphonse Areola was among the players hugely concerned about their loved ones.

“I had family watching the game,” he said. “We were a bit worried about them, you know? Security is the most important thing in a stadium specially in this kind of event and we were worried about our families. We were very worried about our families. It’s just about security and it was a bit too open for the opposing fans. At the end, they managed to stop them.”

He added that the players were justified in stepping in, before saying: “When families or fans are coming to the stadium we don’t want to see things like that. They want to enjoy the event and we want to enjoy it with them as well.”

After the game, manager David Moyes said: “I can’t explain what happened and why it happened. Players were involved because it was the family section… that was probably the reason for the reaction.

“I don’t want that in any way to blight the night because the West Ham fans weren’t looking for trouble. Hopefully they’ll (UEFA) look into it. My family were there and I had friends in that section. You’re hoping they would try and get themselves away from it… I didn’t recognise it because I was too happy.  Security wanted to take me inside but I had to make sure my players weren’t involved.”

After last week’s first leg, the family of Alkmaar manager Pascal Jansen was attacked at the London Stadium.

On Thursday after his side’s defeat, he reflected, “I feel a little bit ashamed that it happened in our stadium. You have to stay in control of your emotions. A few players were worried because they had family members in the stands and I can imagine what they felt.”

Former West Ham stars Joe Cole and Carlton Cole condemned the actions, with the pair speaking to BT Sport.

Joe Cole called for action from UEFA, as he said: “It’s absurd. Ridiculous grown men, AZ Alkmaar fans attacking the fans where families were sitting, our friends and colleagues. The players tried to break it up. You have to look at UEFA and AZ Alkmaar with things like that. Turning up with balaclavas throwing punches, it’s just ridiculous. The players are rightfully concerned, families, friends, kids over there. Ridiculous in the modern game, pathetic.”

“People talk about hooliganism in England. We don’t” see things like that, we haven’t for a long time. We get a reputation for it. It’s other clubs in Europe, it’s pathetic. We have friends sitting there. In the modern game, with the cameras in these places, find out who these people are and ban them for life. We were talking about bringing our kids to the final now you second guess when you see things like that.”

Carlton Cole observed, “There was no need for it. West Ham came, did their job, didn’t disrespect them. When a goal like that goes in you’re elated, happy, you can’t suppress feelings. Your family is over there with the fans. You have to understand that. What is that about? It’s the same men that were outside the player’s hotels, setting off fireworks. What are they doing? Chill out.”

AZ Alkmaar legend Robin Van Persie added to the criticism, sticking up for West Ham fans as he explained, “From the point of view of West Ham, they are allowed to be happy and celebrate together. This should not happen. It’s a big shame. Everyone is here, there’s a winning and losing team. That’s part of it.”

West Ham boss David Moyes added to the conversation, revealing that his players were concerned for their friends and family in the away end.

“We need to wait for the dust to settle,” he said. “The biggest problem was the area players have friends and families in. The players were angry they couldn’t see if they were okay. We need to wait and ask the officials what happened.”

• The Daily Mail report