Two cars were set on fire after an explosion near a synagogue in southern France as authorities “step up security” at Jewish institutions.
A police officer was injured during the “clear criminal attack” on the Beth Yaacov synagogue in La Grande-Motte.
The incident is now being investigated by authorities as “attempted terrorist murder”.
President Emmanuel Macron has vowed to “find the author of this terrorist act and protect places of worship”.
Firefighters, police, and the gendermerie arrived at the scene at around 8.40am on Saturday morning.
France’s Interior Minister Gerald Darmanin said the incident was “an obviously criminal act”.
President Macron wrote on social media: “Thoughts for the faithful of the synagogue of La Grande-Motte and all the Jews of our country.
“Everything is being done to find the author of this terrorist act and protect places of worship.
“The fight against anti-Semitism is a constant battle, that of the united Nation.”
French media report that a man who was caught on CCTV setting fire to the vehicles, was carrying a Palestinian flag and possibly a handgun.
Five people were inside the synagogue at the time, authorities said.
Jewish community leader Yonathan Arfi said the attack was “an attempt to kill Jews”.
Tensions have risen across France with a number of anti-Semitic incidents over recent months.
It comes after a man was shot dead in May after a synagogue in the north-western city of Rouen was set on fire.
Back in 2015, two days after the attacks on the Charlie Hebdo magazine, four people were murdered in an attack on a kosher supermarket.