Pallade Veneta - UK police say almost 900 arrests made at Palestine Action demo

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.

The government in July proscribed Palestine Action under the UK's Terrorism Act of 2000 following several acts of vandalism, including against two planes at a Royal Air Force base, which caused an estimated £7 million ($10 million) in damage.

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.

Of the 33 people arrested for non-terror offences, 17 were for assaults on police officers, the force said.

The organisers of the protest, the campaign group Defend Our Juries (DOJ), said the "Lift the Ban" rally had been "the picture of peaceful protest".

Many of those detained for showing support for Palestine Action appeared to be older people.

Most face six months in prison if convicted but organisers of the rallies could be sentenced to up to 14 years if found guilty.

Five members of Defend our Juries were arrested earlier this week ahead of the protest.

Ex-interior minister Yvette Cooper, who oversaw the ban, has accused Palestine Action of orchestrating "aggressive and intimidatory attacks against businesses, institutions and the public".

Cooper has also suggested that some supporters of Palestine Action "don't know the full nature of this organisation, because of court restrictions on reporting while serious prosecutions are under way".

The ban does seem to have increased support for what was previously a little-known organisation.

"It's so important for me that groups that are called terrorist groups must be terrorist groups," said 60-year-old greengrocer Philip Hughes, holding a placard that read, "I oppose genocide. I support Palestine Action".

"You cannot go and use terrorism laws to go and stop an organisation who object to something that you have done," he told AFP.

The rallies came as Israel launched new strikes on Gaza, with the stated aim of seizing Gaza City to defeat the militant group Hamas.

R.Zarlengo--PV