France is facing a threat of chemical and biological attack on its soil by extremists linked with last week's Paris attack, French Prime Minister Manuel Valls warns.

"The macabre imagination of these commanders has no limits: assault rifles, decapitation, suicide bombings, knife attacks. I say this with the utmost care - but we know there may be a risk of the possibility chemical and biological weapons," Valls said during a session of lower house of national Parliament on Thursday, according to The Local. The French lawmakers are debating on a bill extending the state of emergency for another three months.

"More than ever, it's time for Europe to adopt the text... to guarantee the traceability of movements, including within the union. It's a condition of our collective security," he stated, according AFP.

Valls remarks in Parliament follow the carnage in the French capital on Friday that killed 129 people. Shortly after the Paris terror attack, President Francois Hollande declared a state of emergency in the country.

Officials at interior ministry are still working on verifying the fact that the suspected mastermind of the Paris attacks, Abdelhamid Abaaoud, was among those killed in a police raid. Three suspected terrorists were killed and five arrested in a raid in an apartment in a suburb in Paris on Wednesday, as HNGN reported previously.

In related development, the Belgian security authorities have conducted half a dozen raids in the capital of Brussels in connection with the Paris attacks, reported Associated Press. They are reportedly searching for one of the bombers, Bilal Hadfi, who is believed to be linked with the attack on Stade de France stadium.