At least one person was killed when a man took hostages in a supermarket in the southwestern French town of Trebes on Friday, the mayor told BFM TV.
Another person was hurt but their condition was not known, Mayor Eric Menassi said. The hostage-taker was now alone with one police officer in the supermarket and all other hostages had been freed, he told BFM.
LCI TV said the second victim was also dead and that 12 people were injured.
A police source had said earlier that eight people were being held hostage and that the hostage-taker had shot at a police officer.
BFM TV said the hostage-taker has claimed allegiance to Islamic State. The Paris prosecutor's office said counter-terrorism prosecutors were investigating the incident but did not comment on the possible Islamic State allegiance.
Earlier, the Interior Ministry had said security forces were carrying out an operation at a supermarket in southern France. Interior Minister Gerard Collomb was on his way.
'There is an ongoing situation near Carcassone...in the town of Trebes, where shots have been heard and a man entrenched himself in a supermarket,' Prime Minister Edouard Philippe said. 'It's a serious situation.'
The UNSA police union also said on Twitter a police operation was under way after an individual had earlier shot at four officers in the Carcassone region, wounding one of them.