ISTANBUL, Turkey — Hundreds of thousands of people across several European cities marched Sunday against Israel and in support of Palestinians and the interception of a flotilla’s attempt to reach Gaza.

Istanbul held the largest of multiple demonstrations being staged in Turkey. Footage showed crowds walking from the iconic Hagia Sophia to the banks of the Golden Horn, where they were greeted by dozens of boats decked in Turkish and Palestinian flags. The marchers called for Muslim solidarity with Palestinians following midday prayers in front of the former Byzantine cathedral, now converted to a mosque.

The protests were among others planned Sunday in European cities to mark the second anniversary of the Hamas-led, October 7, 2023, invasion of southern Israel that killed 1,200 people, mostly civilians, and triggered the ongoing war in the Gaza Strip. The thousands of terrorists who burst into the country also abducted 251 people as hostages, of which 48 remain in captivity in Gaza, 20 of them believed still alive.

The Hamas-run Gaza health ministry says more than 66,000 people in the Strip have been killed or are presumed dead in the fighting so far, though the toll cannot be verified and does not differentiate between civilians and fighters. Critics of Israel accuse it of committing genocide in Gaza, which it adamantly denies. Israel says it seeks to minimize civilian fatalities and stresses that Hamas uses Gaza’s civilians as human shields, fighting from civilian areas including homes, hospitals, schools, and mosques.

In the Turkish capital Ankara, protesters held up flags and placards condemning the “genocide” in Gaza. “This oppression, which began in 1948, has been continuing for two years, turning into genocide,” Recep Karabal of the Palestine Support Platform told crowds in the northern city of Kirikkale, referring to the year of Israel’s declaration of independence.

Support for Palestinians is widespread in Muslim-majority Turkey and President Recep Tayyip Erdogan is a leading critic of Israel’s military operations in Gaza. Erdogan has long backed Hamas and does not regard the group as terrorists.

In the Netherlands, an estimated 250,000 people, most dressed in red, gathered in Amsterdam to press the government to take tougher action against Israel.

Sunday’s protest and march through the Dutch capital comes less than four weeks before national elections. Two “Red Line” demonstrations in The Hague earlier this year also drew tens of thousands of people.

After packing the central Museum Square, the protesters walked through the city center, holding Palestinian flags and peace emblems. One placard read, “Ashamed of the government.”

The Dutch government has long been a staunch supporter of Israel, but has in recent months been more critical as international support for Israel has ebbed. On Friday, Foreign Minister David van Weel said it was unlikely he would grant an export license to send parts for F-35 fighter jets to Israel.

“The bloodshed must stop. And that we unfortunately have to stand here because we have such an incredibly weak government that doesn’t dare to draw a red line. That’s why we are here. In the hope that it helps,” protester Marieke van Zijl said.

Marjon Rozema, a spokesperson for Amnesty International, one of the protest organizers, called for the use of “all economic and diplomatic means to increase pressure on Israel.”

Since a similar rally in May, the Dutch government has slowly changed its stance against Israel, imposing travel bans on far-right National Security Minister Itamar Ben Gvir and Finance Minister Bezalel Smotrich in July, accusing them of inciting violence against Palestinians and calling for an “ethnic cleansing” of Gaza.

Last month, the government said it planned to ban imports of goods produced in Jewish settlements in the West Bank and has supported the European Commission’s plans to suspend trade-related measures in a European Union agreement with Israel.

Meanwhile, the leader of the largest party in parliament, anti-Muslim populist Geert Wilders, has repeatedly voiced unwavering support for Israel.

In the Bulgarian capital Sofia, demonstrators marched with signs including “Gaza: Starvation Is a Weapon of War” and “Gaza Is the Biggest Graveyard of Children.”

Organizers said they wanted to “pay tribute to the heroes of the Global Sumud Flotilla,” including Bulgarian activist Vasil Dimitrov.

“Our society – and the world – needs to hear that we stand with the Palestinian people,” protester Valya Chalamova said.

Israel intercepted the flotilla last week, preventing some 40 vessels from reaching Gaza.

Moroccans took to the streets of the capital Rabat in support of the Palestinians in Gaza, many wearing Arab keffiyehs. An Israeli flag was burned near the front of the march as people called for a reversal of the kingdom’s decision five years ago to normalize relations with Israel.

Protesters demanded the release of the flotilla activists, including Moroccan human rights defender Aziz Ghali, who remains in an Israeli prison, having refused voluntary deportation. More than 470 activists, including Swedish climate campaigner Greta Thunberg, were detained in the 42 Sumud vessels when the Israeli navy stopped them. The activists are to be deported.

In Britain, meanwhile, hundreds of people rallied to mark Hamas’s 2023 attack and mourn the victims of an attack on a synagogue in Manchester that killed two and seriously injured four others.

A crowd gathered outside Manchester Cathedral, holding Israeli and UK flags and signs calling for the release of hostages held by Hamas. Another large rally was held in London.

Paris also saw an outpouring of support for the hostages held by Hamas. Hundreds of demonstrators, many waving or draped in Israeli flags, marched through the city’s streets shouting “Free the hostages.”

A day after mass demonstrations across Spain, thousands of people held smaller marches in several cities, calling for an “end to genocide” and trade relations with Israel.

Rallies in Santiago and Gijon, both in the north of Spain, were among the largest, with several thousand attendees. In Gijon, a group of women marched carrying white bundles symbolizing the bodies of children killed in Gaza.

Sunday’s demonstrations came a day after hundreds of thousands marched in Rome, Barcelona and Madrid in a show of growing international outrage at Israel’s two-year military campaign in Gaza. Smaller rallies took place in Paris, Lisbon, Athens and Skopje, North Macedonia, and in London and Manchester.

Israel and Hamas have both signaled eagerness for a deal under a plan recently laid out by US President Donald Trump to end the war. Delegations are reportedly preparing to meet in Egypt on Monday for talks on the 20-point ceasefire agreement.