LONDON (AP) — Police in London said Friday that they have broken up a wedding attended by 400 people — despite a nationwide lockdown that bars households from mixing.

The Metropolitan Police force said officers found hundreds of people packed into the north London school with blacked-out windows on Thursday night. The school’s principal had died from the coronavirus last year.

The force said that “following enquiries it was established that the group had gathered at the location for a wedding.”

Weddings are allowed only in “exceptional circumstances” — such as one partner being dangerously ill and — with a maximum of six people attending.

Police said the organizer could face a 10,000-pound ($13,600) fine. Many guests fled as police arrived, but five people who attended received 200-pound fines.

The Yesodey Hatorah Senior Girls’ School, a state-funded Orthodox Jewish high school, said in a statement that it was “absolutely horrified about last night’s event and condemn(s) it in the strongest possible terms.”

The school said its hall had been leased to an outside organization and “we had no knowledge that the wedding was taking place.”

U.K. Chief Rabbi Ephraim Mirvis condemned the rule-breaking event.

He tweeted: “At a time when we are all making such great sacrifices, it amounts to a brazen abrogation of the responsibility to protect life and such illegal behaviour is abhorred by the overwhelming majority of the Jewish community.”

The school’s principal, Rabbi Avrahom Pinter, died in April after contracting the coronavirus.

Pubs, restaurants and entertainment venues in Britain are closed, and people are required to stay largely at home, as part of restrictions to curb a new surge in the virus. The U.K. has recorded almost 95,000 COVID-19 deaths, the highest toll in Europe.