Five people detained after last week's massacre in Nice are due to appear before a judge Thursday, as France is set
to pass a law extending the state of emergency.
The government is scrambling to reassure a jittery population after the country's third major attack in 18 months killed 84 people out celebrating Bastille Day.
Four men and one woman aged between 22 and 40 are due to appear before the court for links to Tunisian Mohamed Lahouaiej Bouhlel who ploughed a truck into the crowded promenade in Nice.
They include a 40-year-old whom Bouhlel had known for a long time and a 38-year-old Albanian, detained along with his girlfriend and suspected of providing the attacker with an automatic pistol.
A 22-year-old man who received an SMS from Bouhlel shortly before he began his rampage will also appear in court, as well as another man who had been in contact with Bouhlel over weapons.
Like Bouhlel, none of those detained were known to French intelligence prior to the attack.
France's National Assembly and Senate are also set to pass a bill extending the state of emergency -- which gives police extra powers to carry out searches and place people under house arrest -- for six months.
It is the fourth time the security measures have been extended since Islamic State jihadists struck Paris in November, killing 130 people at restaurants, a concert hall and the national stadium.
On Wednesday, MPs also voted to allow authorities to search luggage and vehicles without prior approval from a prosecutor and to allow the police to seize data from computers and mobile phones.
The legislation also makes it easier for authorities to shut down places of worship where calls for violence and hate are made.
The Islamic State group has said the Tunisian driver was one of its "soldiers" but investigators say that while he showed a recent interest in jihadist activity, there was no evidence he acted on behalf of the extremist group.
The group Wednesday posted a video apparently shot in Iraq, where IS holds swaths of territory, showing two French-speaking jihadists threatening more attacks against France.