Pro-Palestinian protesters clashed with police in Paris on Saturday as they defied a ban on a planned rally against violence in the Gaza strip.
A Reuters photographer said demonstrators in northern Paris launched projectiles at riot police, who responded by firing teargas canisters and stun grenades. Demonstrators also climbed on top of a building and burned an Israeli flag.
President Francois Hollande earlier said he had asked his interior minister to ban protests that could turn violent after demonstrators marched on two synagogues in Paris last weekend and clashed with riot police.
"That's why I asked the interior minister, after an investigation, to ensure that such protests would not take place," he told journalists during a visit to Chad.
In defiance of the ban, large crowds gathered in northern Paris chanting "Israel, assassin" until they were dispersed by tear gas.
Peaceful rallies were also held in more than a dozen other cities, from Lille in the north to Marseille in the South.
"This ban on demonstrations, which was decided at the last minute, actually increases the risk of public disorder," the Greens Party said in a statement. "It's a first in Europe."
Interior Minister Bernard Cazeneuve justified bans in Paris and the Mediterranean city of Nice by saying the security risk was too great, prompting outrage from left-wing and pro-Palestinian groups.
Foreign Minister Laurent Fabius responded to criticism France was biased in favour of Israel, which sent ground forces in on Thursday after 10 days of air and naval barrages failed to stop rocket fire from Gaza.
"In no way does this mean that the French government has taken a position against the Palestinians," he told journalists during a visit to Jordan.
On Saturday, Israeli tanks and bulldozers dug in across a mile-wide strip of Gaza's eastern frontier, and Palestinian officials said military strikes had killed more than 300 people, most of them civilians.
Elsewhere in Europe, a man set off a security alert in Geneva when he stopped a tram to retrieve bags that included a book with a radical Islamist image in it, police said.
The incident coincided with some 300 pro-Palestinian protesters gathering in front of the U.N.'s European headquarters in the Swiss city.
The Israeli-Palestinian conflict has contributed to growing tensions between France's Muslim and Jewish populations, both of which are the largest in Europe.
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, with many citing rising anti-Semitism as a factor.