A man armed with a knife killed two people at the main train station in the Mediterranean port city of Marseille on Sunday before being shot by soldiers patrolling there, local officials said.
"Two victims have been stabbed to death," regional police chief Olivier de Mazieres told AFP, referring to the attack which occurred at 1:45 pm (1145 GMT).
Local prosecutor Xavier Tarabeux said the knifeman had been shot by soldiers, while the Marseille police urged people in the city to avoid the area around Saint-Charles station.
The deaths came with France still on high alert following a string of terror attacks which began in January 2015 when jihadist gunmen stormed the offices of the satirical weekly Charlie Hebdo, killing 12.
The government has since launched Operation Sentinelle, deploying about 7,000 troops across the country to guard high-risk areas such as transport hubs, tourist sites and religious buildings.
The knifeman is believed to have shouted "Allahu Akbar" (God is Greatest) before assaulting passers-by, a source close to the investigation told AFP on condition of anonymity.
The attacks since 2015 have left 239 people dead, according to an AFP count before Sunday's incident.
French Interior Minister Gerard Collomb posted on Twitter that he would travel to Marseille immediately.