PARIS (AP) — French President Francois Hollande called on Internet service providers to take action against the spread of anti-Semitism online.

During a visit to France's Holocaust Memorial on Tuesday, Hollande said Internet service providers cannot ignore anti-Semitic and Holocaust- denial theories that are disseminated on social networks. Otherwise, he says, "they will be regarded as accomplices."

Hollande also called European and international leaders to define new regulations with penalties for Internet service providers which do not comply.

Concerns about anti-Semitism have risen after a kosher supermarket was targeted in the country's deadliest attacks in decades. Four Jewish people were among the 17 people killed by the three gunmen, who also died.

Hollande expressed his "anger" and "bitterness" during a ceremony in the presence of five survivors of the Nazi concentration camps. "How in 2015 can we accept that we need armed soldiers to protect the Jewish people of France?" he said.

Synagogues, Jewish businesses, schools and cultural centers will be protected as long as necessary, he promised. France has deployed 10,000 troops to protect sensitive sites, nearly half of them to guard Jewish schools.

A report released Tuesday by a Jewish organization said the number of anti-Semitic acts doubled last year in France. They increased to 851, up from 423 in 2013, according to the Jewish Community Security Service.