A total of 890 people have been arrested in London during a protest this weekend in support of the banned group Palestine Action, the UK capital’s Metropolitan Police said, Reuters reports.

The force said 857 people had been arrested under anti-terror laws for supporting a proscribed group during Saturday’s demonstration, with an additional 33 arrested for other offences, including assaults on police officers.

“We have a duty to enforce the law without fear or favour. If you advertise that you are intending to commit a crime, we have no option but to respond accordingly,” Deputy Assistant Commissioner Claire Smart said in a statement.

Critics, including the United Nations, have condemned the ban as legal overreach and a threat to free speech, but ministers insist that people are still able to attend pro-Palestinian marches.

“The contrast between this demonstration and the other protests we policed yesterday, including the Palestine Coalition march attended by around 20,000 people, was stark,” added Smart.

“You can express your support for a cause without committing an offence under the Terrorism Act or descending into violence and disorder, and many thousands of people do that in London every week.”

An estimated 1,500 took part in the Palestine Action protest outside parliament, with the Met condemning the “intolerable” abuse it claims its officers suffered.