Pro-Palestinian demonstrators staged protests in London, Berlin, Paris, Ankara and Istanbul Saturday to call for a ceasefire in Gaza and castigate Israel after its military intensified its assault against Hamas.
In London, television footage showed large crowds holding sit-down protests blocking parts of the city centre, before marching to Trafalgar Square.
Protesters held "Freedom for Palestine" placards and chanted "ceasefire now" and "in our thousands, in our millions, we are all Palestinians".
Police said they had made 11 arrests. One person was arrested for displaying a placard that could incite hate, contrary to terrorism legislation.
Britain has supported Israel's right to defend itself after Hamas killed 1,400 people and took more than 240 hostage in an Oct 7 assault in southern Israel.
Echoing Washington's stance, Prime Minister Rishi Sunak's government has stopped short of calling for a ceasefire, and instead advocated humanitarian pauses to allow aid into Gaza.
In central Paris, thousands marched to call for a ceasefire with placards reading "Stop the cycle of violence" and "To do nothing, to say nothing is to be complicit."
It was one of the first, big gatherings in support of Palestinians to be legally allowed in Paris since the Hamas attack of Oct 7.
French authorities had banned some previous pro-Palestinian gatherings due to concerns about public disorder.
France will host an international humanitarian conference on Gaza on Nov 9 as it looks to coordinate aid for the enclave.
"We came here today to show the people of France's solidarity with the Palestinian people and our support for peace, for a peace solution with two states, an Israeli state and a Palestinian state," said Antoine Guerreiro, a 30-year old civil servant.
Wahid Barek, a 66-year old retiree, lamented the deaths of both Israeli and Palestinian civilians.
"I deplore civilian deaths on both sides. Civilians have nothing to do with these actions. It really is shameful," he said.
In Berlin, demonstrators waved Palestinian flags, demanding a ceasefire. One woman marched with her arm in the air, her hand covered in fake blood.
Hundreds of protesters gathered in Istanbul and Ankara, a day before a visit to Turkey by US Secretary of State Antony Blinken for talks on Gaza.
Turkey, which has sharply criticised Israel and Western countries as the humanitarian crisis has intensified in Gaza, supports a two-state solution and hosts members of Hamas. Ankara does not consider Hamas a terrorist organisation, unlike the United States, the European Union, and some Gulf states.
In Istanbul's Sarachane park, protesters held banners saying "Blinken, the accomplice of the massacre, go away from Turkey," with a picture of Israeli Prime Minister Benjamin Netanyahu and Blinken together with a red "X" mark on it.
"Children are dying, babies are dying there, being bombed," said 45-year-old teacher Gulsum Alpay.
Footage from Ankara showed protesters gathered near the US Embassy, chanting slogans and holding posters which read: "Israel bombs hospitals, Biden pays for it."