PARIS (Reuters) - Anti-Semitic threats and incidents have more than doubled so far this year in France, said the interior minister at a rally on Sunday to protest a violent attack on a young Jewish couple.

Three men were detained by police and appeared before an investigative judge on Wednesday in relation to the day-time home invasion in the Paris suburb of Creteil in which a 19-year-old woman was raped.

Her 21-year-old boyfriend, who was tied up during the robbery, said the men targeted the apartment because they knew the residents were Jewish and believed there would be money and valuables inside.

Speaking to a crowd of several hundred protesters, France's Interior Minister Bernard Cazeneuve said the government would defend the Jewish community with "all its force".

"We must make the fight against racism and anti-Semitism a national cause," he said.

France has the largest Jewish population in Europe, having grown by nearly half since World War Two to total some 550,000 Jews, according to the community's umbrella group CRIF.

But violent incidents like the murders of three Jewish children and a rabbi by Islamist militant gunman Mohamed Merah in 2012, and clashes at pro-Palestinian rallies in Paris in July have disturbed some in the Jewish community.

In the first three months of 2014 more Jews left France for Israel than at any other time since the Jewish state was created in 1948, citing economic hardships in France's stagnating economy but also rising anti-Semitism as a factor.

Roger Cukierman, the head of Crif, called on the government to do more to address the problem.

"We feel that something has changed: it's no longer just graffiti or minor incidents, these are death threats [against the Jewish community]," he told BFM TV.

"It cannot go on like this."

(Reporting by Leila Abboud and Emmanuel Jarry; Editing by Raissa Kasolowsky)