The Middle East crisis may have fuelled anti-Semitism
The attacks in the past two days follow a spate of anti-Semitic attacks across Europe, fuelling fears that anti-Jewish feelings are on the rise again.
The success of National Front leader Jean-Marie Le Pen in the first round of the French presidential elections is thought to have given an impetus to far-right movements across Europe.
A petrol bomb was thrown at a synagogue in Berlin's Kreuzberg district late on Sunday.
The fire was quickly extinguished by staff at the building.
The synagogue was previously targeted in October 2000, when paving stones were thrown at the windows.
Germany's Central Council of Jews called on the German authorities to fight threats against the Jewish community with all legal, political and police means.
Swastikas
In Britain, a synagogue was desecrated with swastikas, windows were smashed and excrement left in an attack on north London's Finsbury Park Synagogue between 27 and 28 April.
A swastika was scrawled on the rabbi's lectern at the synagogue, surrounded by defiled prayer shawls, skull caps, broken glass and torn prayer books.
"We take very seriously any allegation of anti-Semitic activity and will act swiftly and decisively against those who carry them out," a police spokeswoman said.
"This is the first incident in the country that resembles what's happening on the continent [Europe]," a spokesman for Britain's Chief Rabbi Jonathan Sacks told the Independent newspaper.
"In terms of desecration, this is one of the most disturbing attacks we have seen," Mr Sacks said.
Suspicious fire
A fire destroyed a warehouse at a Jewish school near Paris on Sunday, and police are investigating to find out if it was caused by arson.
There were no casualties in the blaze at the Tipheret Israel institution in the northern Paris suburb of Sarcelles, which includes a school with some 250 students.
The school, which was empty at the time, had already been targeted earlier this month.
Police say more than 300 suspected anti-Jewish acts have been reported since March 29, amid tensions between the country's 700,000 Jews and five million Muslims - the largest populations of both in western Europe.
Already this year, synagogues in the cities of Marseille, Strasbourg, Lyon, Montpellier and Paris have been firebombed or vandalised.
Synagogues have also being desecrated in Belgium and Russia recently.
The attacks on Jewish institutions across Europe have coincided with Israel's military offensive in the West Bank.
Last week, an umbrella group of international Jewish organisations demanded better protection.