An armed man took hostages in a supermarket in southern France on March 23 after opening fire earlier on police nearby, officials and police say.
Reports say at least one person was killed and another one was seriously injured in the incident in the small town of Trebes, south of Toulouse. Prime Minister Edouard Philippe said it appeared to be "a terrorist act."
The alleged attacker was still holed up in the supermarket and it was unclear how many other people were inside with him.
The suspect first fired six shots at police officers who were on their way back from jogging in the city of Carcassonne, said Yves Lefebvre, head of the SGP Police-FO police union.
One police officer had a shoulder injury but it was not serious, Lefebvre said.
The suspect then went to a supermarket in nearby Trebes, where he shot and killed one person and shot another who is in life-threatening condition, Lefebvre said.
Lefebvre's account could not me immediately verified from other sources.
Special police units were sent to the scene and local authorities blocked roads and urged residents to stay away.
Interior Ministry spokesman Frederic Delanouvelle said there is one suspect and police are trying to subdue him. He provided no details of how many people were taken hostage.
The Paris prosecutor's office said counterterrorism investigators were taking over the probe but did not provide details about why.
The move came after unconfirmed media reports that the assailant claimed he belonged to the Islamic State extremist group.
French Interior Minister Gerard Collomb was heading to the scene, security sources said.