France Hunts Down Terrorist Sleeper Cell Suspects

France is tracking down hundreds of people believed to belong to terrorist sleeper cells, including al Qaeda and the Islamic State.

French Interior Minister Bernard Cazeneuve, the country's top security official, said 400 suspects have been identified.

One of the main concerns for authorities is how to prevent disgruntled criminals or disaffected citizens from being radicalized.

Cazeneuve is leaving for the United States Wednesday to enlist the aid of Internet and social media giants in efforts to curb propaganda videos used to recruit and indoctrinate people.

"Ninety percent of those who commit terrorist acts fall into it after regularly consulting websites or blogs that call for or provoke terrorism," Cazeneuve told The Associated Press. "We won't be able to deal with this subject by always brushing the dust under the rug. At some point the dust gets thicker than the rug."

At least two of the men involved in January's Charlie Hebdo terror attack are believed to have been radicalized in jail, as was the man behind the shootings in Copenhagen last weekend.

France wants new measures to give intelligence services more leeway to monitor suspects' electronic communications.