LILLE, France Vandals desecrated 148 graves in the Muslim section of a military cemetery in northern France, hanging a pig's head on one of the headstones, police said on Sunday.
French President Nicolas Sarkozy called the attack "a hateful act" and around 100 police were sent to the Notre-Dame de Lorette cemetery near Arras to hunt for clues.
State prosecutor Jean-Pierre Valensi said the vandals struck overnight, daubing insults on the graves.
"They directly referred to Islam and there were also insults directed at the justice minister," Valensi said, referring to Rachida Dati, whose parents came from North Africa.
The desecration came almost exactly a year after youths daubed Nazi inscriptions and swastikas on Muslim tombs in the same cemetery in Ablain Saint-Nazaire.
France's political class united in denouncing the vandalism.
"This is a most unacceptable act of racism and the president shares the pain of France's Muslim community," Sarkozy's office said in a statement. Prime Minister Francois Fillon called it a "revolting act" and said those responsible would be found.
Police arrested two men over the 2007 attack and sentenced them each to a year in prison.
Notre-Dame de Lorette is one of France's biggest World War One military cemeteries and was built on the site of a battlefield where many French and German soldiers died between October 1914 and October 1915.
During World War One, France mobilized about 600,000 colonial subjects, including many Muslims from Algeria and Tunisia, of whom 78,000 were killed. Some 1.2 million French soldiers were killed in all during the war.
France is home to 5 million Muslims, Europe's largest Muslim community, making up 8 percent of France's population.
The MRAP anti-racism group said this latest desecration showed that "Islamophobia" was taking root in France.
(Reporting by Pierre Savary; writing by Crispian Balmer; Editing by Jon Boyle)