Four held in France over 'imminent' attack

France remains on high alert after wave of attacks that began 2 years ago, claiming around 200 lives

French anti-terrorist police today arrested four people in southern France on suspicion of preparing what Interior Minister Bruno Le Roux said was an "imminent" attack.

The arrests in Montpellier and the nearby town of Marseillan "foiled a plot to carry out an imminent attack on French soil," Le Roux said in a statement

A police source said the four -- who included a 16-year-old girl -- were arrested after buying acetone, a highly flammable liquid that can be used to make bombs.

The other suspects were all men, aged 20, 26 and 33, the source said.

"It seems that they intended to go through with it and to make several explosive devices."

The teenager had used social media to try to find ways of travelling to Syria to join up with jihadists, the source said, adding that the 20-year-old had been her mentor and was under surveillance.

France remains on high alert after a wave of attacks that began two years ago, claiming more than 200 lives.

Last week, a soldier shot and wounded a machete-wielding attacker who lunged at him outside the Louvre museum in Paris while shouting "Allahu Akbar".

Investigators have identified the man as an Egyptian and are trying to establish whether he had any link to a jihadist group.

Le Roux has said that French authorities have foiled "no fewer than 13 plots involving more than 30 individuals", including women and minors, since the Bastille Day truck massacre in the Riviera city of Nice that claimed 86 lives.

Three female jihadists were arrested in September after the discovery of gas cylinders packed in a car near Paris's Notre Dame Cathedral.

In November, police broke up a terror ring plotting an attack in France, jailing four Frenchmen and a Moroccan who had pledged allegiance to the Islamic State group (IS).

France, one of the most active members of the US-led coalition fighting the Sunni extremist group, has been the worst hit among European countries targeted by attacks claimed or inspired by IS.

France's parliament voted in December to extend a national state of emergency until July 15, after this year's presidential and parliamentary elections.

It was the fifth extension of the state of emergency, which gives police extended powers of search and arrest.

Security and fears about Islamic extremism are key issues ahead of the two-round presidential election in April and May.