In less than a week after the Paris attacks, French police have managed to track and kill one of the most-wanted Islamic State jihadists and a "ringleader" of the carnage, Abdelhamid Abaaoud.

However, as investigators weave together a complex web of clues pointing to a sophisticated logistical operation that took place under the nose of European intelligence officers, several burning questions remain.

French leader Francois Hollande has donned the cloak of war chief after the Paris carnage, but has come under fire from the right-wing opposition for wasting time since attacks in January.

A semblance of political unity after the devastating attacks on Friday which left 129 dead has quickly unravelled in a marked shift in the mood seen after attacks on Charlie Hebdo magazine and a Jewish supermarket 10 months ago.

The longtime owner until two months ago of the Bataclan concert hall, site of the worst of last week's Paris attacks and where some of rock's edgiest names have played, hopes it lives on as a free-spirited venue.

Joel Laloux sold the music hall in September after running it for nearly 40 years and now lives in Israel, where he learned of Friday's hostage-taking and massacre during a rock concert there.

In the Brussels bar they ran before the authorities closed it down for being a drug den a few weeks ago, brothers Brahim and Salah Abdeslam were known to be fond of drink and a joint, according to friends.

As they drank their beer in Les Beguines, their nightspot in the Belgian capital's largely immigrant Molenbeek area, there was no sign in their behavior that they were radical Islamists who would take part in the Paris attacks.

Prime Minister Manuel Valls warned Thursday that France was at risk of a chemical or biological weapons attack, as lawmakers voted to extend a state of emergency imposed after the Paris carnage.

The fate of the suspected mastermind of Friday's attacks was still uncertain after a huge police raid in a northern district of the French capital on Wednesday that left at least two people dead.

Belgian Prime Minister Charles Michel on Thursday rejected criticism of his country's security services over the Paris attacks, saying Belgian intelligence led to a huge raid in France targeting the suspected mastermind.

"I do not accept the criticisms which were aimed at denigrating the work of our security services," Michel said in a speech to parliament in which he unveiled new security measures.

Much about Abdelhamid Abaaoud's path to armed Islamic radicalism remains mysterious.

In the words of Koen Geens, the Belgian justice minister, he mutated from a student at an upscale Brussels school into "an extremely professional commando," one seemingly able to slip across borders at will. Someone who openly mocked the inability of Western law enforcement agencies to catch him.

U.S. intelligence warned in May that the Islamic State had developed the capability to carry out the kind of attack claimed by the extremist group in Paris and explicitly picked out the alleged mastermind.

An assessment published by the Office of Intelligence and Analysis, in coordination with the FBI, makes reference to and pictures Abdelhamid Abaaoud, the suspected ringleader of Friday's coordinated suicide bombings and shootings in the French capital that killed at least 129 people.

Russia submitted a revised draft U.N. resolution Wednesday on fighting the Islamic State group that France said could be partially included in its own Security Council measure following the Paris attacks.

Agreement from the 15-member council on a single draft resolution that lays out the international approach to defeating IS extremists would mark a significant step after months of disagreements between the West and Russia

Israeli Prime Minister Benjamin Netanyahu called for "a global solution" to terrorism in a phone call with Francois Hollande on Wednesday to express his solidarity after the Paris attacks, the French presidency said.

Netanyahu "wanted to convey a message of support and stressed that terrorism was a global problem requiring a global solution," the presidency said, five days after Paris was rocked by gun and suicide attacks that killed 129 people.