Police in Belgium on Friday arrested Salah Abdeslam, the Frenchman who became one of Europe's most wanted criminals after playing a key role in and escaping alive from the terrorist attacks that left 130 people dead in Paris last November.
"Salah Abdeslam was arrested ... and he was formally identified," French President Francois Hollande announced in the Belgian capital Brussels, where he had happened to be for an EU summit on migration.
"Salah Abdeslam is directly linked to the preparation, the organization and, alas, the perpetration of the [Paris] attacks," Hollande said, adding that he expects French authorities to ask Belgium for his extradition.
The 26-year-old was at one point suspected of having joined his brother in targeting restaurants and bars during the Paris attacks, but his exact role in the violence has never been publicly disclosed. It is believed that at the very least he offered logistical support to the attackers.
A manhunt for Abdeslam had been under way since mid-November, after he was brought back from Paris to Belgium by two acquaintances following the attacks, which targeted the Stade de France stadium, the Bataclan concert hall, restaurants and bars.
There had been media reports that he may have escaped to Syria - a stronghold of the Islamic State extremist group, which claimed responsibility for the Paris attacks.
But Abdeslam was arrested in Molenbeek, the same Brussels neighbourhood where he grew up and lived before the November attacks. He was hiding in an apartment owned by a friend's mother, the broadcaster RTBF reported.
Abdeslam has been "slightly injured" and was taken to hospital to get treatment for an injury to his leg, said Thierry Werts, a spokesman for the Belgian federal prosecution. According to RTBF, Abdeslam was at the Saint-Pierre hospital in Brussels.
Earlier in the week, investigators had found Abdeslam's fingerprints in a Brussels apartment where a shootout with police had taken place. Gunmen had opened fire on police on Tuesday as they attempted to search the flat in the southern neighbourhood of Forest.
A 35-year-old Algerian armed with a Kalashnikov was killed during that incident, while two suspects escaped. It was not immediately clear Friday if one of those suspects was Abdeslam.
The dead suspect, Mohamed Belkaid, had previously been sought in connection with the Paris terrorist attacks, Belgian prosecutors announced on Friday shortly before launching the operation that led to Abdeslam's arrest.
Belkaid was "most probably" the person using the false identity of Samir Bouzid, who had ties to Abdeslam, the prosecutors said.
Abdeslam was taken into custody with four other people, including three members of the family who was hosting him in Molenbeek.
The other suspect, who uses the alias Amine Choukri, was also slightly injured and taken to hospital for treatment, prosecutors said. He had been controlled by police together with Abdeslam in Germany in October, Werts said.
All the detained suspects will be questioned by police before decisions are made about whether they should remain in custody, according to the spokesman.
Werts said more details would not be released so as not to compromise the investigation.
"It is an intense, meticulous, professional work that has been done," Belgian Prime Minister Charles Michel said, lauding the work of his country's security and intelligence services.
The arrest showed that "all those who allowed, organized or facilitated" the Paris attacks were "much more numerous" than initially expected, Hollande added.
The two leaders had gathered in Michel's office on Friday evening to follow the Molenbeek police operation, which featured gunfire and explosions, until it ended.
US President Barack Obama was among those who congratulated Hollande Michel on the arrest. Obama said his country "stands together with Belgium and France in our shared struggle against the scourge of terrorism," the White House said.
The United States has assisted France and Belgium with their investigations into the Paris attacks, according to White House spokesman Josh Earnest.
The threat of terrorism remains "very high" in both France and Belgium, Hollande warned. He announced that his country's defence council would meet on Saturday morning, as he vowed to continue the fight against jihadist networks.
Michel has also called a meeting of Belgium's security council on Saturday at 10 am (0900 GMT), the Belga news agency reported.