Paris Prosecutor Francois Molins' office said 27-year-old Abdelhamid Abaaoud was identified based on skin samples, but authorities did not know how he died. His body was found in the apartment building targeted in the chaotic and bloody raid in the Paris suburb of Saint-Denis on Wednesday.
Three police officials say a woman who died in the raid was Abaaoud's cousin. One said Hasna Aitboulahcen is believed to have detonated a suicide vest after a brief conversation with police officers.
The official confirmed an audio recording, punctuated by gunshots, in which an officer asks: "Where is your boyfriend?" and she responded angrily: "He's not my boyfriend!" Then loud bangs are heard.
The exact relationship between Abaaoud and Aitboulahcen was not clear.
The bodies recovered in the raid were badly mangled, with a part of Aitboulahcen's spine landing on a police car, complicating formal identification, according to one of the officials.
The officials all spoke on condition of anonymity because they were not permitted to divulge details of the investigation.
PHOTOS: Raid targets Paris mastermind
Police launched the operation after receiving information from tapped phone calls, surveillance and tipoffs suggesting that Abaaoud was holed up there. Eight people were arrested in the raid.
With France still reeling from the Friday attacks that killed 129 people and wounded hundreds of others, Prime Minister Manuel Valls warned Thursday that Islamic extremists might at some point use chemical or biological weapons, and urged lawmakers to extend a national state of emergency by three months.
"Terrorism hit France not because of what it is doing in Iraq and Syria ... but for what it is," Valls told the lower house of Parliament. He added, "We know that there could also be a risk of chemical or biological weapons."
Valls did not say there was a specific threat involving such weapons. Elsewhere in Europe, jittery leaders and law enforcement moved to protect their populations as Rob Wainwright, director of the European Union's police coordination organization Europol, warned of "a very serious escalation" of the terror threat in Europe.
In Italy, Foreign Minister Paolo Gentiloni said law enforcement was searching for five people flagged by the FBI in response to a U.S. warning about potential targets following the Paris attacks.
The State Department issued a warning Wednesday that St. Peter's Basilica in Rome, Milan's cathedral and La Scala opera house, as well as churches, synagogues, restaurants, theaters and hotels had been identified as "potential targets."
Danish and Norwegian police were asked to be on the lookout for a man Swedish authorities said is wanted in connection with an investigation into "preparation for a terrorist offense." Sweden's Security Service, known as SAPO, said the request was not linked to the Paris attacks.
In Belgium, where many of the Paris attackers lived, Prime Minister Charles Michel announced a package of additional anti-terror measures, and said 400 million euros ($427 million) would be earmarked to expand the fight.
He told lawmakers that security personnel will be increased and special attention will be paid to eradicating messages of hate. He also called for more international cooperation, and said he wants to amend the Belgian constitution to extend the length of time terror suspects can be held by police without charge.
"All democratic forces have to work together to strengthen our security," Michel said.
In Belgium, authorities launched six raids in the Brussels region Thursday linked to Bilal Hadfi, one of the three suicide bombers who blew themselves up outside the Stade de France.
An official in the Belgian federal prosecutor's office told The Associated Press the raids were taking place in the suburb of Molenbeek and other areas of Brussels. The official, who spoke on condition of anonymity because the investigation is continuing, said the actions were focusing on Hadfi's "entourage."
French Foreign Minister Laurent Fabius urged the international community to do more to eradicate the Islamic State group, which claimed responsibility for the attacks on a rock concert, Parisian cafes and the national stadium.
Fabius, speaking on France-Inter radio, said the group "is a monster. But if all the countries in the world aren't capable of fighting against 30,000 people (IS members), it's incomprehensible."
France has stepped up its airstrikes against extremists in Syria, and French military spokesman Col. Gilles Jaron said Thursday that French forces have destroyed 35 Islamic State targets in Syria since the attacks on Paris. Next week, French President Francois Hollande is going to Washington and Moscow to push for a stronger international coalition against IS.
Speaking after the seven-hour siege in Saint-Denis, Hollande said that France was "at war" with the Islamic State group.
In its English-language magazine, Islamic State said it will continue its violence and "retaliate with fire and bloodshed" for insults against the Prophet Muhammad and "the multitudes killed and injured in crusader airstrikes."
Molins, the Paris prosecutor, said Wednesday that investigators found a cellphone in a garbage can outside the Bataclan concert hall in eastern Paris where 89 of the victims of Friday's carnage died. It contained a text message sent about 20 minutes after the massacre began. "We're off, it's started," it read.
Molins said investigators were still trying to identify the recipient of the message.
French authorities have said most of the Friday attackers - five have been identified so far - were unknown to them. But two U.S. officials said that many, though not all, of those identified were on the U.S. no-fly list. The officials spoke on condition of anonymity because they weren't authorized to discuss the issue publicly.
A Spanish security official said French authorities had sent a bulletin to police across Europe asking them to watch out for a Citroen Xsara car that could be carrying Salah Abdeslam, whose brother, Brahim, was among the attackers who blew themselves up.
French authorities declared a state of emergency after the attacks, and security forces have conducted 414 raids, making 60 arrests and seizing 75 weapons, including 11 military-style firearms, the Interior Ministry said. Parliament was expected to vote by the end of the week to extend the state of emergency.
The state of emergency expands police powers to carry out arrests and searches, and allows authorities to forbid the movement of persons and vehicles at specific times and places.
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