The Belgian extremist suspected of masterminding the deadly attacks in Paris died a day ago along with his female cousin in a police raid on a suburban apartment building, French officials said, adding it was still not clear exactly how he died.
The body of Abdelhamid Abaaoud, 27, was found in the building targeted on Wednesday in the chaotic, bloody raid in the Paris suburb of Saint-Denis and was identified based on skin samples, the Paris prosecutor's office said.
Abaaoud ended up near Paris after reportedly being in Syria but officials have not said how he managed to travel across so many borders en route to the French capital.
In addition, authorities have not detailed his exact whereabouts or actions during the deadly rampage that killed 129 people last week in Paris.
Interior minister Bernard Cazeneuve said France did not know before last week's deadly attacks that Abaaoud was in Europe, but said he was believed to be behind four of six attacks thwarted since spring by French authorities.
Three police officials told the Associated Press that a woman who died in the police raid was Abaaoud's cousin.
One said the woman, Hasna Aitboulahcen, is believed to have detonated a suicide vest in the building 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 responds angrily: "He's not my boyfriend!" Then loud bangs are heard.
The bodies recovered in the raid were badly mangled, with part of Aitboulahcen's spine landing on a police car, slowing down the identification process, according to one of the officials.
French police launched the operation after receiving information from tapped phone calls, surveillance and tip-offs suggesting that Abaaoud was holed up in the apartment. Eight people were arrested in the raid.
In Belgium, authorities launched six raids in the Brussels region on 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 said the raids were taking place in the suburb of Molenbeek and other areas of Brussels. The official said the actions were focusing on Hadfi's "entourage."
With France still reeling from the attacks that killed 129 and wounded hundreds, France's lower house of parliament, the National Assembly, has voted to extend a state of emergency for three months. The measure now goes to the Senate, where it is likely to be approved.
The state of emergency expands police powers to carry out arrests and searches, and allows authorities to forbid the movement of people and vehicles at specific times and places.
Prime minister Manuel Valls had pressed for the state of emergency extension, warning that Islamic extremists might use chemical or biological weapons.
"Terrorism hit France not because of what it is doing in Iraq and Syria ... but for what it is," Mr Valls told politicians. "We know that there could also be a risk of chemical or biological weapons."
Mr Valls did not say there was a specific threat against France involving such weapons, however.
Elsewhere in Europe, jittery leaders and law enforcement moved to protect their citizens as Rob Wainwright, director of the European Union's police co-ordination agency 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 US warning about potential targets following the Paris attacks. The US state department issued a warning on Wednesday that St Peter's Basilica in Rome, Milan's cathedral and La Scala opera house, as well as churches, synagogues, restaurants, theatres and hotels, had been identified as "potential targets".
Danish and Norwegian police were asked to be on the lookout for a man who Swedish authorities said is wanted in connection with an investigation into "preparing for a terrorist offence". 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 euro (£280 million) would be earmarked to expand the fight.
Mr Michel told politicians that security personnel will be increased and special attention will be paid to eradicating messages of hate. He also called for more international co-operation, 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," Mr Michel said.
French foreign minister Laurent Fabius urged the international community to do more to eradicate the Islamic State group, which has claimed responsibility for the November 13 attacks on a rock concert, Parisian cafes and the national stadium.
Mr 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 air strikes against extremists in Syria, and French military spokesman Colonel Gilles Jaron said that French forces have destroyed 35 IS targets in Syria since the attacks on Paris.
French president Francois Hollande is going to Washington and Moscow next week to push for a stronger international coalition against IS. Speaking after the seven-hour siege in Saint-Denis, Mr Hollande said that France was "at war" with IS.
In its English-language magazine, IS said it will continue its violence and "retaliate with fire and bloodshed" for insults against the Prophet Mohammed and "the multitudes killed and injured in crusader air strikes".
Francois Molins, the Paris prosecutor, said that investigators found a mobile phone in a rubbish bin outside the Bataclan concert hall in eastern Paris where 89 attack victims died. It contained a text message sent about 20 minutes after the massacre began. "We're off, it's started," it read.
Mr Molins said investigators were still trying to identify the recipient of the message.
Seven of the Paris attackers died on the same night as the attacks. French authorities have said most of the attackers - five have been identified so far - were unknown to them. But two US officials said that many, though not all, of those identified were on the US no-fly list.
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.