Dozens of people were reported killed Friday night in shootings at several places in Paris, the BBC and The Associated Press reported.
Explosions were also heard outside the Stade de France, where the French and German national soccer teams were playing, the AP said.
The BBC and AP reported that about a dozen people were killed at a restaurant.
The AP said more people were killed at the Bataclan arts center, with reports of 100 hostages also being taken. Late Friday, automatic gunfire was heard from outside the music venue there, AP reported.
It was unclear who was behind the attacks.
President Francois Hollande closed France's borders and declared a state of emergency.
International leaders, including President Barack Obama, are set to visit Paris at the end of the month for UN climate change talks.