French police are hunting a suspect following an explosion that injured 13 people in a busy pedestrian street in Lyon.

The country’s counter-terrorism prosecutor, Remy Heitz, said an investigation has been launched into “attempted murderer in relation with a terrorist undertaking”.

He said no group has claimed responsibility for the explosion.

France Explosion
Scene of the explosion in Lyon (Sebastien Erome/AP)

Regional authorities said 13 people suffered mostly minor injuries, including 11 who were still in hospital on Saturday morning.

French President Emmanuel Macron called the explosion an “attack” on Friday.

Mr Heitz described video surveillance that shows the suspect heading towards Lyon city centre on a bicycle on Friday afternoon.

The man was seen arriving on foot, pushing his bike, in the pedestrian Victor Hugo street. He was seen leaving a paper bag on a concrete block in the middle of the street near a bakery, Mr Heitz said.

The suspect immediately returned to his bike and left by the same path. One minute later, the explosion shattered the glass of a cooler in the bakery.

Investigators at the scene have found screws, metallic balls, a triggering device that can be used remotely and plastic pieces that may come from the explosive device.

Police issued an appeal for witnesses and described the suspect as “dangerous”.