The three men and a woman, described by security services as radical Islamists, were arrested in Paris and a northern suburb in dawn raids.
Police arrested 14 people after they torched tyres and blocked bridges in the Channel port in protests against thousands of migrants gathered there.
Six migrants and two activists from No Borders group will stand trial Monday after they were arrested for storming a ferry in the Channel port.
Official said Salah Abdeslam, wanted for his part in the massacres, was not among the five arrested in and around Brussels on Sunday and Monday.
Prosectors said two men were arrested, one a French national, in connection with the November attacks, bringing total of suspects held to eight.
Five employees are held over violent protest last week against the airline's plan to axe jobs, which notably left two of its directors bare-chested.
The trio, who include a 17-year-old boy and a former navy rating, allegedly planned to post video of the decapitation on the internet.
Malian police said among the 20 'presumed jihadists' arrested is a man wanted for an attack in March on a Bamako restaurant that left five dead.
One of the men, arrested near the south-west town of Bayonne, is wanted in connection with the shooting in 2010 of a French policeman.
Bosses of ride-hailing firm face court accused of 'misleading commercial practices' and complicity in 'illegal exercise of the taxi profession'.
Three men and a policewoman are held for questioning over their relationships with Amedy Coulibaly who shot four people dead in January.
The five arrests came after a 15-year-old turned himself into police for the attack on the cemetery in the eastern Alsace region of France.
The suspects from Toulouse and Albi are believed to have handled questionable money transfers and recruited candidates to wage jihad.
Officials say the seven men and a woman detained in the Paris and Lyon areas are not suspected of links to the Paris attacks of January 7th to 9th.
Two of the men arrested in the southern town of Lunel had returned from Syria, according to French police sources.