British nationals in Marseille are being urged to take care after a knifeman killed two women at the city's main railway station.
The man, who was later shot dead by soldiers, shouted "Allahu akbar", according to witnesses cited by France's Minister of the Interior.
Gerard Collomb, who said authorities do not know if it was a terrorist incident, said police have video of the attack which took place at Saint Charles station on Sunday, the Associated Press reported.
He said it showed a man attacking one woman, running away, and then coming back and attacking a second woman.
In a statement, the Foreign Office said: "Following an incident at Marseille St Charles train station we are advising British nationals in the vicinity to take care and follow the advice of the local security authorities."
The attacker was shot dead by soldiers who had been patrolling inside the station, according to AP.