Despite already experiencing a number of terrorist attacks this year, such as the Charlie Hebdo shootings — both carried out by French citizens — officials are thought to be concerned about the potential of large-scale terror attacks from within.
A source from French security agency DGSI told Le Canard Enchaîné newspaper that there were fears of "an upcoming 11 September" attack in the country, while another intelligence source told the Daily Telegraph "airlines have been warned of a possible attack on a plane with an anti-tank missile. But pilots are unsure how to take evasive action."
'There's a lot of Alienated Immigrant Kids'
As a result of recent attacks and fears about increased Islamist radicalization in France, it has been reported that the French army is looking to make its presence felt in so-called extremist hotspots, in order to wrest back control from jihadist extremists.
"There are a lot of alienated and angry fourth-generation immigrant kids in the suburbs and the prospect of radicalization is increasingly likely," the security source said.
There are also concerns about the prevalence of highly dangerous weapons in some parts of France, especially in areas near Paris' main airport, sparking fears of an attack on aircraft.
"We're dealing with highly-organized networks of militant Islamists embarked on a campaign of violence and determined to intensify it," the source added.
Integration Failure
Critics have argued that France failed to integrate groups of migrants from predominately Islamic backgrounds into wider society, which has led to an outbreak of racial and ethnic tensions in the country.
Long-held concerns about the effects of such alienation were revealed in 2010, when leaked US diplomatic cables showed frustration over the lack of integration between different ethnic groups in France.
The cables from August 2005 showed how the US embassy in Paris raised concerns about the effects alienation of France's Muslim community could have.
"France not only has a problem with integration or immigration; it also needs to act to give Muslims a sense of French identity," the cable read.
"We believe that if France, over the long term, does not succeed in improving prospects for its minorities and give them true political representation, it could become weaker, more divided and perhaps inclined toward crises."
With France's security services facing a difficult battle to stop further attacks, many are concerned that preventative action aimed at stopping Islamist extremism may be too difficult to reverse.