Six people, including a five-year-old girl, have been injured after a masked yob launched a grenade into a French beauty salon.

Terrifying footage shows the moment the man forces his way into the salon in Grenoble after fighting with a woman by the entrance.

The hooded thug dressed all in black can be seen with the grenade in between his legs as he appears to pull the pin before throwing it inside at around 3pm on Friday.

As the man flees along with a gang of friends, the footage shows the explosion inside the salon on Gambetta, a busy street in the southeastern city near the busier Gustave-Rivet square.

At least one person managed to escape the building before the blast, while six others were found injured inside.

Julie Esthétique, the owner of another beauty salon located just a few doors down, told France 3 Isère: 'I heard a huge explosion and three young girls screaming; they were with a child.

'Right now, I can't even see the street because there are so many fire trucks and people; it's not very reassuring.

'There are so many people, and it's complete chaos.' 

Alain, who lives on the same street as the salon, described the 'monstrous boom' as the grenade went off.

'I went downstairs quickly. We saw people screaming, covered in blood and panicking,' he said.

French police are investigating the daytime attack and are hunting for at least two suspects.

Grenoble prosecutor Etienne Manteaux has revealed that he doesn't believe the grenade was thrown with deadly intent, describing it as an 'act of intimidation'.

Mr Manteaux issued a statement obtained by Le Dauphiné after visiting the scene. 

It reads: 'An individual entered the shop and threw an explosive device. 

'It wasn't a standard grenade, a military grenade.

'It was more of a blast device, but it caused significant damage, as it shattered the window. 

'No one was seriously injured, and no one was hospitalized.

'This confirms that it wasn't a conventional grenade, but rather an act of intimidation, which is obviously quite serious. 

'Investigators already have some promising leads to track down the perpetrators.

'What is significant and worrying, and demonstrates an escalation in the criminals' lack of inhibition and the publicity they seek for their actions, is that the second individual was filming the first [the one who threw the device into the shop], and the footage is already circulating on social media.

'All of this seems truly unbelievable. Rest assured of the determination of the investigative services, and the justice system is working to shed light on these events.'