French public prosecutor Francois Molins told a news conference in Paris on Friday that an Islamic State" (IS) commander sent instructions to a group of suspected terrorists in France to acquire arms using encrypted electronic apps.

Five people were taken into custody last Sunday in Strasbourg and Marseille and were suspected of planning a terrorist attack.

"A Strasbourg commando team, and also a man arrested in Marseille, were given instructions to acquire arms," Molins said, adding that they intended to attack Paris around December 1.

While making the arrests, police also found automatic weapons, he said.

On Thursday, French anti-terror authorities took the unusual step of holding the men in custody without charge beyond the normal maximum period, using a recent anti-terrorism measure.

State of emergency

Last July, a self-radicalized extremist drove a truck into crowds watching Bastille Day fireworks in the southern city of Nice, killing 86 people.

Two weeks later, two jihadists in their 20s claiming to be IS followers slit the throat of 84-year-old priest Jacques Hamel at a church near the northern city of Rouen.

France has been under a state of emergency since "IS" attackers killed 130 people in Paris in November last year, including rock music guests at the Bataclan concert hall.

ipj/sms (AP, Reuters, AFP)