Valls said on Monday authorities suspect new terrorist attacks are being planned in Europe.

"We know that operations were being prepared and are still being prepared, not only against France but other European countries too," he said, adding that France would be living with the fear of further attacks for some time to come.

"Once again the terrorists have attacked France, the French people, young people. Many young people are dead," he said.

The French prime minister also said authorities were raiding the homes of suspected militants responsible for the slaughter in Paris.

His statement comes after France launched its largest airstrike against "Islamic State" (IS) forces in Syria to date overnight Sunday.

IS claimed responsibility for the attacks in Paris, which claimed the lives of 132 people.

blc/jil (Reuters, AFP, dpa)