PARIS — French authorities opened a terrorism investigation Saturday after an arson attack on a synagogue in a southwestern Mediterranean town injured a police officer. Security forces were searching for a suspect.

Two cars parked at the Beth Yaacov synagogue complex in the seaside resort town of La Grande Motte near Montpellier were set ablaze just after 8 a.m. Saturday, antiterrorism prosecutors said in a statement.

Firefighters discovered additional fires at two entrances to the synagogue. A police officer who walked up to the site was injured after a propane gas tank in one of the vehicles exploded, the statement said.

Five people, including the rabbi, who were present in the synagogue complex at the time of the attack were unharmed, it added.

Prosecutors were investigating the attack as an attempted assassination linked to a terrorist group and destruction of property with dangerous means, and a crime planned by a terrorist group with an intent to cause harm, the statement said.

The mayor of La Grande Motte, Stephan Rossignol, said that investigators were reviewing the city’s surveillance videos and said that a lone suspect was spotted at the site of the attack.

“We don’t know if the individual has left the city or if he is still in the city,” Rossignol said in an interview with broadcaster France Info. “The individual in question did not manage to get inside the synagogue, even though that was clearly his objective.”

President Emmanuel Macron said the synagogue attack was a “terrorist act” and assured that “everything is being done to find [its] perpetrator.”

“The fight against antisemitism is a constant battle,” Macron said on social media platform X.

Acting Prime Minister Gabriel Attal said called the attack an “an act of antisemitism.”

“Once again our Jewish fellow citizens are being targeted,” Attal said in a post on X. “Faced with antisemitism, faced with violence, we will never let ourselves be intimidated.”

Acting Interior Minister Gerald Darmanin ordered police reinforcements to protect Jewish places of worship and said the attack was being treated as “attempted arson” that is “clearly a criminal act.”

“I want to assure our Jewish fellow citizens of my full support and say that at the request of President Emmanuel Macron all means are being mobilized to find the perpetrator,” Darmanin posted on X.

He ordered more police officers deployed at Jewish places of worship around the country following a surge of antisemitism since the start of the Israel-Hamas war in October.

Darmanin and Attal were expected to travel to Le Grand Motte later Saturday.