As the Hamas-Israel conflict has spilled over into Europe, protection for the Jewish community has been stepped up following a rise in anti-Semitic incidents.
On the same weekend that Hamas attacked Israel, a synagogue in central Madrid was vandalised with anti-Semitic graffiti.
The graffiti, which read 'Free Palestine' next to a crossed-out Star of David, was removed hours later.
The Platform Against Antisemitism condemned the incident, but declined to give the exact location of the synagogue in order to prevent further acts.
"These have been very difficult days, full of fear and deep uncertainty. It is a heartbreaking situation and we are in constant contact with our relatives in Israel," Estrella Bengio, president of the Jewish community of Madrid, told Euronews.
As the conflict has spilled over into Europe with a series of demonstrations in several capitals, protection for the Jewish community has been stepped up.
Bengio says they have taken security measures to protect both members and institutions, and have shared "common sense" advice to ensure the safety of their community.
Constant surveillance in Barcelona
The Barcelona police have flanked the building of the Israeli community in the Catalan city.
Anyone who tries to approach has to pass through a police checkpoint, and then a second checkpoint where they are asked if they are carrying weapons.
The community itself has cancelled activities for young people planned for the coming weeks.
"The situation is tense, we are living a tragedy. The fear is there, but our job is not to let it in and to go on with our lives," Rabbi David Libersohn, who lives in Barcelona, told Euronews.
"We follow the precautions that the police give us, they do the risk assessment. Now there is more security and we are also very careful, we do the things we have to do," he added.
For the rabbi, instilling fear is a form of terrorism. And that is exactly what former Hamas leader Khaled Mashal's recent call for a "day of rage" against Zionism and a "global jihad" has achieved.
According to Spanish media reports, the country's interior ministry has reinforced its anti-terrorism alert to level 4 on a scale of 5, with special units tasked with keeping a close eye on synagogues or Jewish schools.
The Madrid synagogue was not the only one to be vandalised on the Iberian peninsula.
On Wednesday, graffiti reading "Free Palestine" and "End Israeli Apartheid" was found on the Mekor Haim Kadoorie synagogue in the Portuguese city of Porto.
The graffiti appeared just hours after a pro-Israel demonstration in the city.
More than 20 arrests in France
France is home to Europe's largest Jewish community and since Saturday the country has recorded around 50 anti-Semitic acts.
"There are people in front of synagogues, in large numbers, shouting threats," French Interior Minister Gérald Darmanin told a television programme.
"We have detected drones with a camera entering school playgrounds," he added.
The government, which wants to 'avoid an escalation', has announced that more than 20 people have been arrested in connection with the incidents, including three foreigners who will be expelled from the country.
Some 10,000 gendarmes and police are currently guarding over 500 "sensitive" sites, such as synagogues and schools, according to the Interior Ministry.
While a pro-Israel demonstration took place in Paris on Monday, French police used tear gas and water cannon to break up a banned demonstration in support of the Palestinian people on Thursday.
France is also home to Europe's largest Muslim community, but the government had vetoed the demonstration because it was 'likely to cause public disorder'.
The situation has caused a political rift in the country. Emmanuel Macron and his government have condemned the Hamas attack, while Jean-Luc Melenchon's left has compared it to the Israeli occupation.
The New Anti-Capitalist Party defended the Palestinian "resistance" without condemning the Hamas attack, statements for which it is being investigated for advocating terrorism.
UK seeks to quell support for Hamas
Three million pounds (€3,471,316) has been pledged by British Prime Minister Rishi Sunak to protect Jewish schools and synagogues.
The Jewish community has said that reports of anti-Semitic incidents have risen by 324% since this weekend's Hamas attack, compared with the same period last year.
Fears of escalating tensions and reprisals have led several Jewish schools in London to suspend classes this week.
One parent told Sky News he would be changing his children's school uniforms: "So it doesn't indicate in any way that they're Jewish".
Pro-Palestinian demonstrations have taken place in the British capital, but Home Office minister Suella Braverman has called for 'the full force of the law' to be used to quell pro-Hamas rallies after videos emerged of people appearing to celebrate the attack on Israel.