Woman named as Ines Madani, who had pledged allegiance to Isis, among trio held after car packed with gas cylinders found

Three women arrested near Paris on Thursday night had been planning an attack on the Gare de Lyon, an official has said.

The women, aged 19, 23 and 39, were arrested in Boussy-Saint-Antoine, a small town 19 miles (30km) south-east of Paris, after they were linked to the discovery of a car packed with gas cylinders parked near Notre Dame cathedral last weekend.

The French interior minister, Bernard Cazeneuve, said the women were “radicalised and fanaticised” and believed to have been preparing “new and imminent violent action”. He said there had been a “race against time” to stop them involving a vast police and intelligence operation.

“France is confronted with a terrorist threat of unprecedented scale,” Cazeneuve said. The changing threat took different forms and was very hard to detect, he added, calling for the “vigilance of all citizens”.

Speaking on Friday morning, an interior ministry official told Reuters: “An alert has been issued to all stations, but they had planned to attack the Gare de Lyon on Thursday.”

The Gare de Lyon, one of the busiest train stations in Paris, is in the south-east of the capital.

The discovery of a Peugeot 607 near Notre Dame carrying seven gas cylinders, six of them full, led to a terrorism investigation and revived fears about further attacks in a country where Islamic militants have killed more than 230 people since January 2015.

The 19-year-old French woman arrested on Thursday night was named by Associated Press as Ines Madani. Her father, who has been known to police in the past for radicalisation, was the owner of the car. On Sunday, he told police that his daughter had disappeared with the vehicle.

Madani had been classed as dangerous by police. Newspaper Le Monde reported that she had been known to police since 2015 for wanting to leave for Syria, where hundreds of people of French and other nationalities have gone to join Islamic State. She had reportedly written a letter pledging allegiance to Isis.

During the arrest, one of the women stabbed a police officer, injuring him in the shoulder, before officers shot and wounded her. TV footage showed an officer leaving the scene carrying a large knife.

The investigation into the discovery of the car continues. Police sources said no detonator device was found in the vehicle, but the diesel canisters raised concerns that the car was planned to explode. Documents with Arabic writing were found in the Peugeot, which had no number plates and was left with its hazard lights flashing.

Several people continue to be questioned. A 27-year-old man and a 26-year-old woman were detained on Wednesday south of Paris and a second couple, a 34-year-old man and a 29-year-old woman, were detained on Tuesday.

Investigators are trying to establish whether any of those arrested and questioned have links with Hayat Boumeddiene, the girlfriend of Amedy Coulibaly, who killed a police officer and four hostages at a kosher supermarket in Paris in January 2015. Boumeddiene left France just before the attacks on the capital and is believed to have headed to Isis-held territory.

Police are also investigating any possible links between the people who have been arrested and Larossi Abballa, who murdered a police commander and his partner at their home outside Paris in July in the presence of their three-year-old son.

Facebook Twitter Pinterest An armed officer watches over tourists outside the Notre Dame cathedral in Paris, near where the Peugeot 607 was parked. Photograph: Christophe Ena/AP

French media said the three arrested women may have been looking to avenge the recent death of the chief Isis propagandist, Abu Muhammad al-Adnani, who had inspired people to launch attacks in the west.

Earlier this week, Florence Berthout, the mayor of Paris’s fifth arrondissement, said the discovery of the car highlighted the need to increase security in the French capital. “Police and army staffing must be stepped up,” she told news channel BFMTV.

The vehicle was left in a zone where parking is strictly prohibited and had remained there for about two hours before it came to the attention of police, after being reported by a waiter at a nearby restaurant, she said.

Thousands of extra police and soldiers have been deployed to protect sensitive sites across France. A state of emergency declared after the coordinated attacks on Paris last November remains in place and gives police extra search and arrest powers, but there has been a continuing political debate about security levels since 85 people were killed when a lorry driver ploughed into crowds celebrating Bastille Day on 14 July in Nice.