Police in London deployed thousands of officers and specialist equipment on Saturday to control crowds around two rival marches and to ensure the day’s main football event—the FA Cup final at Wembley—passed without major disruption, the Associated Press reported. Police said the operation was designed to prevent trouble both between the marches and in the period after the match.

The Metropolitan Police described the policing as a “significant public order policing operation” and said it used at least 4,000 officers, armored vehicles, horses, dogs, drones and helicopters. Police said most of their concerns were centered on central London, where officers worked to avoid crossover between the two marches as tens of thousands of people moved through the city.

One of the marches police sought to keep separate was organized by far-right agitator Stephen Yaxley-Lennon, who is better known by his pseudonym Tommy Robinson. Police also prepared for the annual Nakba demonstration, which commemorates the “catastrophe” associated with the exodus of Palestinians from what is now Israel in 1948, and said they remained on guard for any contact involving splinter groups.

As the afternoon progressed, police said they would be mindful of groups coming into contact and of any trouble following the conclusion of the FA Cup final, which Manchester City won against Chelsea. Police also said prosecutors had been tasked with considering whether protest material—placards, banners and chants—seen on social media could amount to offenses of stirring up hatred.

By 7:30 p.m., police said 43 people were arrested for a variety of offenses. It said a further 22 were arrested at Wembley Stadium, and it added that four officers were assaulted, none seriously, while six people were subjected to hate crime offenses.

British authorities framed the day’s policing in the context of a politically polarized period, saying the marches took place amid heightened tensions after elections last week in which extremes on the right and left advanced across the country. The AP report said protesters were motivated by issues ranging from anger over would-be asylum seekers crossing the English Channel to Israel’s actions in Gaza, where the report cited the Gaza Health Ministry’s figure of more than 72,700 people killed.

The Crown Prosecution Service’s director, Stephen Parkinson, said: “This is not about restricting free speech.” He added that it was “about preventing hate crime and protecting the public, particularly at a time of heightened tensions.” The report said prosecutors were also directed to assess whether protest content could be treated as offenses of stirring up hatred.

In addition to police measures, the U.K. government blocked entry for 11 foreign nationals for the “Unite the Kingdom” rally. The AP report listed right-wing figures who said they had been barred as Polish politician Dominik Tarczynski, Belgian politician Filip Dewinter, anti-Islam commentator Valentina Gomez and Dutch activist Eva Vlaardingerbroek.

Prime Minister Keir Starmer said the government would block people who seek to incite hatred and violence, and he warned of potential consequences for disruption. “We will block those coming into the U.K. who seek to incite hatred and violence,” Starmer said. “For anyone who sets out to wreak havoc on our streets, to intimidate or threaten anyone, you can expect to face the full force of the law.”

Before the rallies, Starmer visited the Metropolitan Police command center to discuss policing arrangements with Met Commissioner Mark Rowley and London Mayor Sadiq Khan. The AP report also said live facial recognition would be used for the first time in a protest policing operation, with cameras set up in Camden, a north London neighborhood that is not on the route of the “Unite the Kingdom” march but which is expected to see significant attendance.