The sonic boom of a fighter jet breaking the sound barrier reverberated through the French capital Paris and nearby suburbs on Wednesday, the Paris police said on Twitter.
"A very loud noise was heard in Paris and in the Paris region. It was not an explosion, it was a fighter jet crossing the sound barrier," Paris police said on their Twitter account, urging people to stop calling emergency phone lines.
The noise, which was heard all across the city and shook windows, rattled Parisians already on edge after a knife attack outside the former offices of the satirical weekly Charlie Hebdo last week that the government has called an act of terror.
According to a Defence Ministry spokesperson, the sound heard all over Paris on Wednesday was caused by a Rafale fighter attending to another aircraft in need. The jet had been authorised to break the sound barrier, the spokesperson added.