Protesters pack London streets demanding an end to the siege of Gaza

People take part in a "March For Palestine" in London on Saturday. Henry Nichols/AFP via Getty Images hide caption

toggle caption Henry Nichols/AFP via Getty Images

People take part in a "March For Palestine" in London on Saturday.

Henry Nichols/AFP via Getty Images

Tens of thousands of protesters marched through central London on Saturday, one of several cities worldwide that's seen over the actions of Israel's military inside Gaza spill out into the streets.

British police estimated that up to 100,000 marchers participated in a rain-soaked rally that started near the city's largest central park and continued down to Whitehall, close to the Parliament and the Downing Street residence of Prime Minister Rishi Sunak.

Counter-terrorism officers were among the one thousand police monitoring the march, watching for signs of support for either Hamas or Hezbollah, both of which are banned in the U.K.

But police said a chant first used by the Palestine Liberation Organization — "from the river to the sea, Palestine will be free" — would be allowed on free-speech grounds, even though Hamas has since adopted it. Police said they would intervene if the chant was used near Jewish cultural centers or synagogues, or was directed at members of the city's Jewish community.

It is more than two weeks since Hamas attacked communities and killed roughly 1,300 people in southern Israel, and its military responded with artillery and aerial bombardments of the Gaza Strip. Aid for those inside the besieged Palestinian enclave was only on Saturday, with several trucks carrying medical supplies and food.

The crowds in London carried Palestinian flags, with participants demanding that Israel end the siege and discontinue airstrikes that have killed more than 4,000 Palestinians and forced more than a million Gazans from their homes. Ahead of the march, officials in the U.K. urged those demonstrating to be conscious of the feelings and grief that many members of Britain's Jewish communities are feeling as well.

In a statement, London's Metropolitan Police said the majority of the protest march had taken place lawfully and without incident, but there had also been several "pockets of disorder and some instances of hate speech." The force has recorded a massive 1,300% increase in reported antisemitic offenses this month, compared to October last year, while reported anti-Muslim crimes have also more than doubled in the same period.

Earlier a German news agency reported that police leaders in Berlin had pre-emptively banned a similar pro-Palestinian rally that had been planned for Sunday, after clashes in recent days between police officers and pro-Palestinian demonstrators. But authorities have allowed a demonstration in support of Israel to gather in the German capital on Sunday.

Other pro-Palestinian demonstrations took place in Rome and Sydney, as they have recently in Washington, D.C., the Jordanian capital of Amman, in Beirut and right across Muslim-majority countries like Morocco, Turkey, Malaysia and Bangladesh.