Even before Wembley was stormed by hundreds of ticketless fans, the approach to the stadium resembled a war zone. “Walking along Wembley Way was one of the worst experiences of the night,” said Francesco, an Italian fan. “It looked like a battleground: trash everywhere, trees being pulled and England fans forcing their way up stairs to the stadium and causing crushes.”

Fans were not allowed into the stadium until 5pm, and by this stage huge queues had formed, with some people standing on broken glass and other debris as tensions mounted.

At the first security checkpoint, Francesco noticed many people getting turned away because they did not have tickets, only to rejoin the queue in the hope of better luck next time.

At 5.15pm Paul Brown, a video reporter, filmed dozens of fans breaching a Covid test and ticket checkpoint between the stadium and Wembley Arena. His video, uploaded to Twitter an hour later, showed stewards being overwhelmed and knocked off their feet.

“Security had no chance,” Brown told the Guardian. “They were a mixture of police and checkers who didn’t look like security guards – they looked like university kids. For every one security point there was one person on duty, so a fan could either go left or right of them, so if the security guard looked left, the fan could go right.”

For ticketless fans, this barrier was the “base camp of Everest”, according to Brown. He said he saw at least 50 fans get though, but he pointed out that they still had to get into the stadium itself. Other witnesses said the stewards gave up checking for Covid tests because there were too many people waiting.

At 5.59pm Dan Dicker, who works in IT, filmed another breach as fans pushed aside five waist-high barriers into a VIP zone for the stadium. His footage, uploaded at 6.16pm, showed dozens of fans getting through, although some later turned back.

Similar footage showed fans dashing through upturned barriers as stewards made vain attempts to stop them. At another makeshift barrier, video showed some fans being beaten with truncheons as others got through. Other people appeared to breach security by climbing up on to the roof of a toilet block or using barriers as a makeshift ladder.

“Once they got through the barriers, fans would have been able to go through the stairs to the outer concourse, but not the stadium,” Dicker said.

When Dicker got to the turnstile with his ticket, someone tried to get into the revolving cage with him, he said. “As I put my ticket in a guy jumped in behind. I turned round and said: ‘No mate, you’re not coming in with me,’ but there would have been loads of people who got through like this.”

Several other witnesses reported the same tactics. Francesco said there were four ticketless fans who forced their way in with him and his girlfriend. “I told the steward and he said 500 had probably got through this gate alone,” Francesco told the Guardian.

Philip Cornwall, a production editor on the Guardian’s sports desk, said: “There were loads of lads hanging about trying to persuade ticketholders to let them squeeze behind them through the turnstiles. The turnstiles are unmanned, so it required the vigilance of the stewards about five yards back to see if this was happening.”

A fan who wanted to remain anonymous said she and her nephew were offered £50 by ticketless fans who wanted to “try and sneak in behind us” at the turnstile. “We ignored them but they did it anyway.”

A more serious breach was to follow. She said: “I watched 100 people storm through a door to get into the stadium and then attacking stewards and fans.” She said the incident took place at gate C.

Video filmed from a concourse under the stadium seating area showed fans storming through a door marked C10 as fans shouted “do your job” to outnumbered stewards. Some of the fans who entered, including one who appeared to be a child, were then attacked by other fans. It is unclear when the video was filmed but it was shared on social media at least half an hour before kick off.

At about 6.50pm Wembley Stadium acknowledged it was “dealing with an incident that occurred at the outer security perimeter area of the stadium”. But at the time it insisted there had been “no security breaches of people without tickets getting inside the stadium”. Later it admitted “a small group of people” had made into the stadium without tickets. It is still unclear how many.

“It was absolute bedlam inside,” said a fan who would only give her name as Laura. “There were people in our seats and too many people in our row, some must not have had tickets.” She said she saw an England fan snatch an Italian flag that was tied to a boy’s neck. “The poor child was with his family and looked terrified.”

More ticketless fans tried to enter at half-time, according to a 50-year-old fan who did not want to give his name. “There was then related disturbances as people found their seats occupied by those without tickets,” he said.

Jon Wilson, an England fan, said it was “the worst football match I have ever experienced – raw aggression the whole way through”. He added: “Wembley Way was appalling. There were no Covid checks to gain entry as staff were too busy dragging a number of people who were forcing the barriers. My 15-year-old son said afterwards: ‘I don’t think I like football.’”