"Fifty-one tombstones were damaged, of which two were broken. The vertical part was separated from the horizontal part or broken," a spokeswoman for the local prefecture said, adding that none of the tombs were broken into. Police had opened an inquiry and called on any witnesses to the incident, which occurred in the Jewish section of the Lille-South cemetery, to come forward, she said.

Interior Minister Francois Baroin condemned the attack, in which several tombstones were knocked over.

"Francois Baroin ... condemns with the greatest firmness the acts committed in the night from Saturday to Sunday," his office said in a statement, adding that the damage was "intolerable".

France is home to western Europe's biggest Jewish and Muslim communities.

The number of anti-Semitic incidents in France jumped sharply in 2007, a Jewish group said in February. A young Jewish man was kidnapped and brutally murdered at the start of the year and other attacks have followed by Muslim gangs in major towns.