France has declared a national state of emergency and has closed its borders after at least 40 people were killed in multiple shootings in Paris.
At least 15 people have been killed near the Bataclan arts centre, where up to 60 people are reportedly being held hostage, French media say.
Three people were killed in an attack at the Stade de France, with some reports suggesting a suicide blast.
Paris authorities have asked people to stay indoors.
Military personnel are being deployed across Paris.
The deadliest attack appears to have targeted the Bataclan concert hall. The BBC’s Hugh Schofield says scores of ambulances have arrived at the scene, suggesting many victims inside.
Other attacks hit Le Petit Cambodge restaurant in the 11th district where a BBC reporter could see 10 people lying on the road, either dead or seriously injured.
Another hit Le Carillon bar not too far away.
An eyewitness told Liberation he had heard more than 100 rounds being fired at a cafe in rue de Charonne.
There are reports of up to six gunmen involved.
President Barack Obama spoke of “an outrageous attempt to terrorise innocent civilians”.
UK PM David Cameron said he was shocked and pledged to do “whatever we can to help”.