LONDON, United Kingdom -- Tens of thousands of pro-Palestinian protesters marched in Britain Saturday calling for a ceasefire as Israel's army intensified its assault on the Gaza Strip. Thousands more demonstrated in France and Switzerland.

As Israel's intense strikes provided cover for its ground forces to step up fighting in Gaza, the United Nations warning thousands more civilians could die.

Israel unleashed its bombing campaign after Hamas gunmen stormed across the Gaza border on October 7, killing 1,400 people, mostly civilians, and seizing more than 220 hostages, according to Israeli officials.

The Hamas-controlled health ministry in Gaza said Israeli strikes had since killed 7,703 people, mainly civilians, with more than 3,500 of them children.

It was the third consecutive weekend that London hosted a large rally in support of Palestinians.

One marcher, Dani Nadiri, 36, said UK Prime Minister Rishi Sunak's call for a "humanitarian pause" in the fighting to allow aid into Gaza and hostages to leave was not enough.

"A full ceasefire needs to happen," Nadiri told AFP. "It's time now to do something rather than let it escalate any further."

The demonstrators gathered at a central point by the River Thames at midday, before making their way to the UK parliament in Westminster.

- 'It can't go on like this' -

Noori Butt, from Luton in southern England, said she just wanted the war to end.

"It can't go on like this. The world is dying and I want lasting peace for everybody. That's the way it should be," said the 38-year-old teacher.

About 100,000 people joined the "March for Palestine" in London according to British media, which also reported scuffles with police.

London's Metropolitan Police deployed more than 1,000 officers to patrol the march.

Police arrested one protester on suspicion of assaulting an officer, and another for making racist remarks and threats to kill.

Expressing support for Palestinians is allowed in Britain but praising Hamas -- a banned in the UK as terrorist organisation -- is not.

Other rallies took place Saturday in Manchester and Glasgow, Scotland.

- Paris marchers defy ban -

Thousands of demonstrators took part in rallies across France on Saturday.

Protesters joined one in Paris, defying a court ban issued on public order grounds. A large contingent of police blocked demonstrators in the centre of the capital.

Among the protesters were elected officials, including a green MP and a far-left lawmaker.

"(The need for) a ceasefire is urgent, to stop killing women, children and men," said Elsa Toure, the deputy mayor of Corbeil-Essonnes, south of Paris.

Demonstrator Samia Orosemane carried a sign with the words: "Where has our humanity gone?"

"It is not right that a ceasefire has not been called, that thousands of civilians are dying and no one is saying anything," she said.

"In the country of human rights, we are prevented from protesting," she said of the ban on the march.

An administrative court on Saturday upheld the ban, citing "the serious risk of disturbing public order" amid "heightened tensions linked to the events in the Gaza Strip with a rise in anti-Semitic acts in France".

There was a 135-euro ($143) fine for taking part. By the evening, police said they had made 21 arrests and issued more than 1,350 fines.

Demonstrators also took to the streets in other French cities.

Organisers said 4,000 marched in the southern city of Marseille, while police put the figure at 1,800.

And in Switzerland, organisers said 7,000 demonstrators gathered in Zurich, with police saying there were "several thousand".

There were 2,000 in Lausanne, 1,800 in Geneva and over a thousand in Bern.