MALMO (EJP)---A threat and an attack against a synagogue in the synagogue of the Swedish city of Malmö last Friday have shocked the Jewish community.

Security has been stepped up after a bomb threat was left at the synagogue and the following day a firecracker exploded outside, shattering three windows but causing no injuries.

A police spokesperson said that the explosion most probably was due to "some kind of firecracker.". He did not characterize the explosive as a bomb.

It was reportedly the second threat to the synagogue in as many weeks.

Fred Kahn, president of Sweden’s Jewish community, which has suffered an exodus because of anti-Semitism, said: "It’s incredibly sad that this should happen again. “We thought we were finished with this sort of thing."

In March 2009 there were violent anti-Israel demonstrations in Malmö when an Israeli tennis team arrived to play Sweden in the Davis Cup.

Rock-throwing protesters were arrested after the city council banned spectators from the event because they said they could not secure the area.

In 2009 an article by a Swedish journalist in the Aftonbladet large circulation daily newspaper accused the Israeli army of killing Palestinian youths to harvest their organs.

According to a press report, the number of anti-Semitic crimes reported in Sweden rose 57 percent last year.

The local newspaper Skanskan wrote that since the beginning of the year there has been an increased threat against Jewish families in Malmö. The feelings of insecurity and lack of personal safety are today so strong that some Jewish families have chosen to leave the city, or even to leave Sweden.

Around 10,000 Jews live in Sweden.