Armed police are raiding a flat in the northern Paris suburb of Saint Denis in an operation believed linked to last Friday's attacks. Paris police said gunfire had been exchanged and some officers had been wounded.
Unconfirmed reports said Abdelhamid Abaaoud, the alleged mastermind of the attacks, is the focus of the operation.
The so-called Islamic State (IS) group has said it carried out the attacks in which 129 people died.
The deadly attacks have put European countries on high alert. On Tuesday evening, a football friendly between Germany and the Netherlands was cancelled shortly before kick-off and the stadium in Hanover evacuated after "concrete" information about a bomb threat, according to the city's police chief.
Part of Hanover railway station was also closed while a suspicious object was investigated.
Meanwhile, two Air France planes heading to Paris from the US were diverted because of security threats. One was sent to Halifax in Canada, the other flew to Salt Lake City in the US state of Utah. Both planes landed safely and the passengers were unharmed.