Pro-Palestinian protesters fought with Paris police officers who blocked the demonstrators from entering two synagogues in the French capital on Sunday.
Prime Minister Manuel Valls called the incidents "inadmissible," adding that "France will never tolerate using violent words or acts to import the Israeli-Palestinian conflict on our soil."
A police spokeswoman said one synagogue was targeted during a service, and worshippers were briefly blocked inside while police pushed protesters back. The spokeswoman said all those inside left safely by Sunday evening.
The protesters were part of a crowd of about 10,000 demanding an end to Israeli strikes on Gaza, and accusing Western leaders of not doing enough to stop them.