London’s police department has arrested nearly four dozen people who attended rival protests in the United Kingdom on Saturday.An anti-Islam rally was organized by right-wing activist Tommy Robinson, while a separate protest was simultaneously held to celebrate Nakba Day. It is an annual day of commemoration and national mourning for Palestinians displaced during the 1948 Arab-Israeli War.At least 65 arrests were conducted during the police operation that covered both protests and an anticipated soccer match at a nearby stadium in London, the Metropolitan Police said on social media around 7:30 p.m. local time. Of those arrests, 43 were conducted at the protests. No details have been provided on which side saw more arrests.

At least four officers were assaulted, according to police, and another six officers were subjected to hate crimes. Both protests concluded Saturday afternoon after a couple of hours.

Metropolitan Police officials described the security operation designed to handle the day of rival protests as “unprecedented.” Roughly 4,000 officers were deployed for the operation.

The police department revealed that planning for the large number of people in one area had been underway for months.