Paris was rattled on September 30 in what was believed to be a blast. However, the police later clarified that the loud sound heard across the city, was the sonic boom of a fighter jet.

The military plane broke the sound barrier, which reverberated through the French capital and nearby suburbs, the Paris police prefecture said on Twitter.

The shockwave rattled windows and was heard in almost every part of the city, leading to a surge in phone calls to police, Reuters reported.

It was not immediately clear why a fighter plane was flying over Paris. A Defence Ministry spokesman confirmed it was a sonic boom but did not immediately offer further comment.

The police urged people not to call emergency services.

Paris has been tense since a knife attack outside the former offices of satirical magazine Charlie Hebdo on Friday.

With inputs from Reuters.