France will have more than 10,000 soldiers mobilised on home soil by Tuesday after 17 were killed in attacks carried out by Islamist militants in Paris last week, Defence Minister Jean-Yves Le Drian said on Monday.

Speaking a day after the biggest French public demonstration ever registered, held to remember the victims, he said France was still at risk of further attacks.

"The threats remain and we have to protect ourselves from them. It is an internal operation that will mobilise almost as many men as we have in our overseas operations," Le Drian told reporters after a cabinet meeting.

The victims, including journalists and police, lost their lives in three days of violence that began on Wednesday with a shooting attack on the political weekly Charlie Hebdo, known for its satirical attacks on Islam and other religions.