A Belgian national who is currently in Syria is suspected of being behind Friday's attacks in Paris, according to a source close to the French investigation. The latest development came amid conflicting reports over whether police had arrested a suspected accomplice in Belgium.
"He appears to be the brains behind several planned attacks in Europe," the source told Reuters, adding that the man, Abdelhamid Abaaoud, was the investigators' best lead as the person likely behind the killing of at least 129 people in Paris on Friday.
According to RTL Radio, Abaaoud is a 27 year-old from the Molenbeek suburb of Brussels, home to other members of the militant Islamist cell that carried out the attacks.
In other developments Monday, there were conflicting reports that Belgian police arrested a suspect called Salah Abdeslam, according to Belgian broadcaster RTL.
While earlier reported that he had been arrested in Molenbeek, where police had conducted raids today, Belgian broadcaster RTBF seemed to contradict reports of an arrest.
Abdeslam is suspected of renting a car used in the attacks. He has been identified as dangerous by French police.
The arrest is a result of a manhunt continuing for those that are suspected of helping the Paris attackers. French police made 23 arrests in a series of overnight raids and seized arms including rocket launchers as part of an investigation into the attacks on Paris, Interior Minister Bernard Cazeneuve said on Monday.
Over the last 48 hours, 104 people were put under house arrest and police conducted 168 raids last night, Cazeneuve told journalists.
"Let this be clear to everyone, this is just the beginning, these actions are going to continue," Cazeneuve said.
Earlier Monday French Prime Minister Manuel Valls told national radio station RTL that French intelligence services had prevented five attacks this year.
The death toll was put 132 on Sunday, but reports on Monday said that increase may have been a counting error.
"We know that more attacks are being prepared, not just against France but also against other European countries," Valls said on RTL radio.French media said police also raided houses in Toulouse, Grenoble and Bobigny.
"We are making use of the legal framework of the state of emergency to question people who are part of the radical jihadist movement...and all those who advocate hate of the republic," Valls said.
On Friday, three coordinated teams of gunmen and suicide bombers carried out the wave of attacks across Paris in what President Francois Hollande called an "act of war" by Islamic State.