Marseille residents took to Twitter on Friday saying sounds resembling those of explosions had been heard in the city. Police later explained that the noise which caused the concern was the sound of a fighter aircraft breaking the sound barrier.

Later AFP cited local police, who said that the loud noise was a fighter aircraft breaking the sound barrier.

Earlier on Friday, alarmed residents tweeted that they heard blasts and that the walls and windows of their houses shook.

According to an AFP journalist on the scene, it was a Rafale jet making a flight test for the army.

Alarmed residents wrote that they have heard blasts and that the walls and windows of their houses shook.

UPDATE - Firefighters and police do not report any ongoing intervention in #Marseille - @laprovence — Ruptly (@Ruptly) 13 января 2017 г.

There has been no confirmation of any explosions from the city rescue services or city council.

Explosion heard in Marseille, cause unknown, firefighters and emergency services have no request to intervene: police via @AFPMarseillehttps://t.co/nYmNRhSkOs — AFP news agency (@AFP) January 13, 2017

“The explosion was felt on the wall [of my house] and the window trembled,” one person wrote on Twitter.

One Marseille resident claimed that there were at least two “powerful detonations” that hit the city.

“I hear the sound of sirens,” one person added.

Deux grosse détonations entendu dans la plupart des quartiers de Marseille #Marseille — Tom Charmasson (@CharmassonTom) 13 января 2017 г.

It is not yet clear where exactly in Marseille the alleged blast or blasts took place.

“I heard a boom [sound],” another person wrote.

J'ai entendu une énorme explosion sur La Valentine à #Marseille, des informations ? — Maxence Rose 🌹 (@pirmax) 13 января 2017 г.

“We also heard an explosion but its origin is a mystery so far,” one firefighter told La Provence.