Armed police are raiding a flat in the north Paris suburb of Saint Denis in an operation linked to Friday’s attacks.
At least two suspects have reportedly been killed, including a woman who blew herself up with a suicide belt. Several explosions and gunfire were heard.
Three people have also been arrested, according to French media reports.
The focus of the operation is reported to be Abdelhamid Abaaoud, the alleged mastermind of the Islamic State-claimed attacks that killed 129 people.
Roads have been blocked off around Rue de la Republique in Saint Denis, in the same district as the Stade de France, where suicide attackers detonated bombs on Friday.
Truckloads of soldiers joined armed police at the scene.
“I’ve been hearing gunshots continuously, like fireworks… There have been some breaks but …..to me it sounds like continuous gunshots,” one resident, Benson Hoi, told the BBC.
At least five people were believed to have been in the targeted third floor flat in Rue de La Republique, French radio RTL reported.
At least two police officers had been wounded.
The operation began at around 04:30 local time (03:30 GMT). Deputy Mayor Stephane Peu urged local residents to stay indoors, saying “it is not a new attack but a police intervention”.
Belgian Abdelhamid Abaaoud, 27, had been thought to have organised Friday’s attacks from Syria, but is now believed to have been one of those in the St Denis apartment.
Earlier, security sources said surveillance video showed a possible ninth assailant during Friday’s attacks.
The video reportedly shows a third figure in the car carrying the group which attacked several bars and restaurants.
It is not clear if this ninth attacker is one of two suspected accomplices detained in Belgium or is someone still on the run.
