"The last nine attacks on French soil were committed by individuals who were unknown to the security services, who were not on a watchlist and were not suspected of being radicalised," Interior Minister Gerald Darmanin told France Inter radio.

France plans to strengthen its counter-terrorism laws by permitting the use of algorithms to detect activity on jihadist and other extremist websites.

Draft legislation was submitted to President Emmanuel Macron and his government at a cabinet meeting on Wednesday, after a wave of Islamist and Islamist-inspired attacks on French soil in recent years, including last Friday.

"The last nine attacks on French soil were committed by individuals who were unknown to the security services, who were not on a watchlist and were not suspected of being radicalised," Interior Minister Gerald Darmanin told France Inter radio.

"That should cause us to ask questions about the intelligence methods we're using," Darmanin added.

France enacted a counter-terrorism law in 2017 to replace a state of emergency declared two years earlier following the attack on Paris by Islamist suicide bombers and gunmen.

The 2017 law, which was subject to review after four years, allowed security agencies to use algorithms to monitor messaging apps, as well bolstering police surveillance measures such as 'home visits' to individuals suspected of terrorism links and the restricting the movement of people

The new bill would render those measures permanent and extend the use of algorithms to websites.

"Terrorists have changed the methods of communication. We continue to be blind, monitoring phone lines that nobody uses any more," Darmanin said.

The Tunisian national who killed a police employee in a Paris commuter town five days ago had watched religious videos glorifying acts of jihad just before carrying out his attack, the anti-terrorism prosecutor has said.

The bill would give security agencies more power to watch over and limit the movements of high-risk individuals after release from jail for two years rather than one.

Furthermore, it would give judges the authority to impose follow-up measures, including psychiatric care, on prisoners who served at least five years for terrorism-related offences in an effort to reduce repeat offences.