A man with a knife attacked people at the main train station in the southeastern French city of Marseille on Sunday, killing two women before soldiers fatally shot the assailant, officials said.
French police warned people to avoid Saint Charles train station, tweeting that an operation was underway. Soldiers and police took up positions outside the station, which was evacuated.
Three police officials said one woman was stabbed to death. Two of the officials said the other woman's throat was slit. The assailant was shot dead by soldiers who were patrolling inside the station. The officials were speaking on condition of anonymity because they weren't authorized to speak publicly about the operation.
The Paris prosecutors' office said that a counter-terrorism investigation has been opened. No further details were immediately given, including the motive for the attack. Interior Minister Gerard Collomb tweeted that he would travel to the scene.
The suspect killed by French soldiers after stabbing two women to death in Marseille, appeared to go by several identities, Marseille mayor Jean-Claude Gaudin told reporters on Sunday.
"I think it was a terrorist attack and the individual who was killed seems to have had several identities," said Gaudin.
A police source added that a digital analysis of the suspect's fingerprints came up with several aliases.
Interior Minister Gerard Collomb, who was also addressing reporters in Marseille along with Gaudin, remained cautious on the nature of the act.
"This could be of a terrorist nature, but we cannot confirm it fully at this stage," said Collomb.
Earlier this month, four American college students were attacked with acid at the same train station in Marseille. At the time, French authorities said the assailant was suffering from a mental illness.
France has been in a state of emergency following a spate of attacks by Islamist militants over the last two years, including attacks in Paris in November 2015 which killed 130 people.
A gunman drove a heavy truck into a crowd celebrating Bastille Day in the city of Nice last year, killing 86 people and injuring scores more.