Story highlights

NEW: "The risk is still very high," the deputy mayor of Paris says

France confirms ringleader Abdelhamid Abaaoud was killed in a raid in Saint-Denis

An attorney for a fugitive suspect's brother says the family doesn't now if he's dead or alive

Paris, France CNN  — 

The ringleader behind the Paris attacks is dead, killed during a dramatic raid that shook a neighborhood and collapsed an entire floor of an apartment building. But French authorities say their work is far from finished.

Six days after a coordinated string of shootings and bombings killed 129 people in the French capital, at least one suspect is still on the run. A series of raids in Belgium and a search of a home on the outskirts of Paris on Thursday were the latest signs of investigators’ efforts to piece together – and take down – the network of terrorists behind the attacks before they can strike again.

And authorities say the threat from ISIS, which claimed responsibility for the attacks and threatened more worldwide, remains real.

“We just now have to be ready for anything, any kind of an attack. … Although we know that the mastermind of the attacks of Paris has been killed, the risk is still very high,” Paris Deputy Mayor Patrick Klugman told CNN’s “Erin Burnett: OutFront” on Thursday.

French officials said the raid Wednesday at an apartment building in the northern Paris suburb of Saint-Denis was a significant step. On Thursday, they confirmed they’d identified the body of Abdelhamid Abaaoud, the ringleader of the Paris attacks, found in the rubble of the apartment.

Official sources in France have also identified a woman who blew herself up during the raid: 26-year-old Hasna Ait Boulahcen, a relative of Abaaoud.

Hasna Aitboulahcen blew herself up at an apartment builder in Saint-Denis.

Friends of her family in their hometown of Aulnay-sous-Bois, on the northeastern outskirts of Paris, said she had lived there until recently. Residents in the area told CNN authorities had taken her mother and brother into custody. And the Paris prosecutor’s office told CNN that police were searching the mother’s home.

Interior Minister Bernard Cazeneuve said Abaaoud “played a decisive role” in the Paris attacks and played a part in four of six terror attacks foiled since spring, with one alleged jihadist claiming Abaaoud had trained him personally.

Wednesday wasn’t the first time authorities had tried to take Abaaoud down. Western intelligence agencies reportedly tried to target Abaaoud in the months prior to the Paris attacks, without success.

A key question now: Are other top ISIS operatives who may have worked with Abaaoud on the Paris plot still on the loose?

Searching for suspects

Authorities have said they believe at least two suspects in the Paris attacks could be on the run.

A source close to the investigation told CNN the search for one of them, Salah Abdeslam, has been extended to include the Netherlands, where Abdeslam had spent time in the past. But a spokesperson for the Dutch justice ministry said the search for Abdeslam had not expanded to the Netherlands, the news website reported.

Wherever he is, attorney Nathalie Gallant, who represents the 26-year-old suspect’s brother Mohamed, said the family hasn’t heard from him and is hoping Abaaoud’s death will persuade him to surrender.

“He’s waiting to know if Salah is dead or still on the run,” she said.

Belgium, where Abdeslam and Abaaoud both lived and spent time together in prison, has also become a key focal point of the investigation.

With pockets of the country seen as fertile ground for jihadist recruiters, it’s where members of a suspected terror cell waged a deadly gun battle in January with police and also where three Americans in August overpowered a radical Islamist gunman on a Paris-bound train.

Investigators there detained nine people in raids across the country Thursday. Some of them, authorities said, were tied to Bilal Hadfi, one of the suicide bombers who died in last week’s Paris attacks.

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France wants wider anti-ISIS coalition

French authorities are using a state of emergency declared by President Francois Hollande to carry out a widespread clampdown on potential terrorist threats, detaining dozens of people, putting more than 100 others under house arrest and seizing an alarming array of weapons.

At the President’s request, France’s lower house voted Thursday to extend the state of emergency for three more months. The bill now goes to the French upper house, or Senate, for an expected vote Friday.

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The Paris attacks and ISIS’ claim of bringing down a Russian passenger jet over Egypt last month have underscored the extremist group’s desire to expand the reach of its terror.

Already part of the U.S-led coalition that’s bombing ISIS targets in Syria and Iraq, France has stepped up its airstrikes on the militants in recent days, and Hollande said Thursday that he wanted the airstrikes to intensify.

On Friday, the U.N. Security Council unanimously adopted a resolution penned by France that gathers international support for counterterrorism efforts, specifically aimed toward ISIS.

Russia has taken military action in Syria independently of the U.S.-led coalition, attacking ISIS but also other groups opposed to Syrian President Bashar al-Assad, a close ally of Moscow.

And France’s interior minister, Cazeneuve, will press the case for more concerted European action, during an upcoming European Union justice council meeting in Brussels.

Talking to French lawmakers Thursday about extending the state of emergency, Valls warned that not taking steps to combat ISIS could have dire consequences. For proof, he pointed to their history of executions, bombings, beheadings and added that the use of chemical and biological weapons can’t be ruled out.

“The way they are killing is constantly evolving,” Valls said. “The grim imagination of those giving the orders has no limit.”

Complete coverage of Paris attacks

CNN’s Atika Shubert contributed from Saint-Denis; Margot Haddad, Paul Cruickshank and Tim Lister contributed from Paris; Jethro Mullen reported and wrote from Hong Kong; Greg Botelho and Catherine E. Shoichet reported and wrote from Atlanta.