PARIS (AP) — Paris police opened fire Tuesday on a woman suspected of making death threats and speaking in support of terrorism on a train into the French capital, the latest security incident in the country that has been on heightened anti-terror alert since a fatal stabbing at a school on Oct. 13 blamed on an Islamic extremist.

Police fired one shot, hitting and seriously injuring the woman, the Paris prosecutor's office said. It said she was hospitalized for emergency treatment.

A police investigation was opened into the exact nature of what the woman allegedly said while riding the RER C suburban train into Paris, and witness testimony will be gathered, the prosecutor’s office said.

It said she is facing potential charges of making death threats, of apologizing for terrorism and of intimidating behavior directed at police.

The woman was dressed in a long robe, known as an abaya, the prosecutor’s office said. Abayas are mainly worn by Muslims.

Another police probe was opened into the shooting, which is automatic when officers use firearms.

Paris police said officers responded after several train passengers phoned the emergency services and reported that a woman was making threats.

Officers lay in wait for the woman at a Metro and suburban train station in eastern Paris that serves the François Mitterrand national library, the prosecutor’s office said.

The shot was fired after she refused to obey police orders, it said.

The train station was evacuated.

In the Oct. 13 school attack, French-language teacher Dominique Bernard was stabbed to death and three other people were wounded.

The alleged attacker had been under police surveillance on suspicion of Islamic radicalization. French anti-terror investigators said the suspect declared allegiance to the Islamic State group before the assault in the northern French town of Arras.