This article is more than 1 year old

This article is more than 1 year old

French police are hunting a suspect believed to have deposited a paper bag containing a device that exploded on Friday, wounding 13 people on a busy pedestrian street in the city of Lyon.

France’s counter-terrorism prosecutor, Remy Heitz, said an investigation has been opened for an “attempted murder in relation with a terrorist undertaking” and “criminal terrorist association”.

He said no group had yet claimed responsibility for the explosion. Regional authorities said 13 people had suffered mostly minor injuries but 11 were still in hospital on Saturday morning.

On Friday, the French president, Emmanuel Macron, called the explosion an “attack”.

Heitz described video surveillance that showed the suspect heading toward the centre of Lyon by bike on Friday afternoon. The man was seen arriving on foot, pushing his bike along the pedestrian-only Victor Hugo street, then leaving a paper bag on a concrete block in the middle of the street near a bakery.

Facebook Twitter Pinterest French police issued this photo from CCTV showing a man wanted in connection with the explosion. Photograph: Police National/Handout/EPA

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

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

Police issued an appeal for witnesses on Saturday with a photo of the suspect from video surveillance. They described the man as dangerous. The man was wearing a cap and sunglasses that partially hid his face.

Local authorities said security has been enhanced in France’s third-largest city, including more police and military patrols.

The Women’s Football World Cup is scheduled to start in France on 7 June. Lyon will host the semi-finals and then the 7 July final. After the explosion, the interior minister, Christophe Castaner, sent instructions for Lyon authorities to strengthen security for “public sites and sporting, cultural and religious events”.

On Victor Hugo street, police removed the cordon around the explosion area and the atmosphere on Saturday was almost back to normal, with people doing their shopping – the only oddity being the chalk lines drawn by forensics on the ground.

“It was scary,” said Gisele Sanchez, owner of a haberdashery close to the bakery. Large wood planks covered her shop window, which was damaged by the blast. Police found in her shop screws, metallic balls and batteries believed to be from the device, yet Sanchez was able to reopen on Saturday morning.

France is jittery over a spate of attacks in recent years, some of them deadly, carried out by people ranging from extremist attackers to mentally unstable individuals. Five people were killed on 11 December in an attack on the Christmas market in Strasbourg, eastern France. The alleged killer, Chérif Chekatt – shot dead by police – had pledged allegiance to Islamic State.