Paris/Brussels: A total of 23 people are in custody with seven detainees identified following a massive manhunt that continued on Monday for surviving members and accomplices suspected to be involved in the Paris terror attacks that claimed 129 lives, media reported.
Belgian special operations forces made an arrest during a raid in Molenbeek, a suburb of Brussels, but failed to apprehend main suspect Belgian-born French national Salah Abdeslam, sought by French authorities, the Belgian federal justice was quoted as saying by state broadcaster RTBF.
However, conflicting reports by another Belgian state-broadcaster RTL claimed that Abdeslam, 26, was arrested after he was seen at a window of a building with his arms up in the air, before police used tear gas to neutralise him.
Details of how Abdeslam was involved in the attack were not disclosed.
The search for the perpetrators of the Paris attacks led authorities across the Belgian border to Molenbeek, impoverished suburb of Brussels with a history of links to terror plots, CNN reported.
At least two roads in Molenbeek, a suburb of the Belgian capital with a substantial Muslim population of mostly Moroccan and Turkish immigrants, were cordoned off by the police in an active standoff since the early hours of Monday.
Belgium's Foreign Minister Didier Reynders said there would be "more action" in Molenbeek -- and urged intelligence services across the rest of Europe "to exchange more and more intelligence", Sky News reported.
The stand-off came as Belgian national Abdelhamid Abaaoud was named the suspected mastermind of the Paris attacks. Abaaoud, currently in Syria, was reportedly also linked to thwarted attacks on a Paris-bound high-speed train and a church.
Meanwhile, French Interior Minister Bernard Cazeneuve said "war" had been declared on France, and that "Anybody who attacks the Republic, the Republic will fight back".
Cazenueve has ordered 104 people to be put under house arrest since the Paris attacks. More than 150 police anti-terror raids conducted in cities across France.
Five of the detainees were identified over the weekend, and on Monday another two were named by the Paris prosecutor as Ahmad al-Mohammad and Samy Amimour.
Al-Mohammad is the name on a Syrian passport found with the remains of one of the attackers, though the man's identity has not yet been verified. The other attackers so far named are all from Europe.
Amimour was said to be facing terrorism charges in France.
Three teams of terrorists staged coordinated attacks at six locations across Paris on November 13, including a concert hall, the Stade de France and at least two restaurants. At least 129 people were killed and 352 others wounded in the attacks. Ninety-nine of the wounded are reported to be in very serious condition.
Two of the total seven dead attackers were identified as Ismael Omar Mostefai, 29, and Bilal Hafdi, aged 20.
In retaliation, the French Air Force carried out bombing missions over IS's stronghold in Syria Raqqa on Sunday and Monday against strategic targets. There were no immediate reports of casualties.