An explosion outside a synagogue in southern France wounded a police officer early on Saturday in what authorities said was being treated as a potential terror attack. 

Security around Jewish sites was tightened following the early Saturday blast outside the Beth Yaacov synagogue in the seaside resort of La Grande Motte, near the city of Montpellier. 

Two cars outside the synagogue burst into flames after a gas canister likely exploded inside one of the vehicles, police said. 

Prime Minister Gabriel Attal said France's national anti-terror prosecutors had been tasked with probing the incident. "La Grande Motte's synagogue was the target of an attack this morning," Attal said in a post on X. 

"An anti-Semitic act. Once again, our Jewish fellow citizens are being targeted."

Earlier, Interior Minister Gerald Darmanin called the incident "an obviously criminal act." He said "all means are being deployed to find the perpetrator." 

A suspect caught on a surveillance camera after an explosion that injured a police officer near a synagogue in southern France Saturday was brandishing a Palestinian flag, AFP news agency reported, citing a source close to the probe.