0520 GMT June 19, 2019
The blast occurred in a pedestrian street in the heart of the city of Lyon just two days ahead of the country's hotly contested European Parliament elections.
Heitz added that the man thought to have planted the device, who was spotted on CCTV footage, was on the run, according to Reuters.
Police investigators said they have not been able to identify the suspect as he was wearing sunglasses and a cap.
French police were on Saturday hunting the suspect, AFP wrote.
President Emmanuel Macron called the explosion that apparently happened from a package packed with shrapnel, an "attack" and sent his interior minister, Christophe Castaner, to Lyon.
Police issued an appeal for witnesses on Twitter as they sought the suspect, a man believed to be in his early 30s on a mountain bicycle caught on security cameras in the area immediately before the explosion.
An image of the man was posted. He was described as "dangerous."
The country's justice minister, Nicole Belloubet, told BFM television it was too soon to say whether the blast was a "terrorist act."
Eleven of the wounded were taken to hospitals. None of the injuries was life-threatening. The casualties comprised eight women, a 10-year-old girl, and four men.
A police source said the package contained "screws or bolts." It had been placed in front of a bakery near a busy corner of two popular streets at around 17:30 p.m. (1530 GMT) Friday, on a balmy spring evening.
The blast occurred on a narrow strip of land between the Saone and Rhone rivers in the historic center of the southeast city. The area was evacuated and cordoned off by police.
"There was an explosion and I thought it was a car crash," said Eva, a 17-year-old student who was about 15 meters (50 feet) from the site of the blast.
"There were bits of electric wire near me, and batteries and bits of cardboard and plastic. The windows were blown out," he said.
'A huge 'boom''
The attack upended last-minute campaigning ahead of today’s European Parliament vote with Prime Minister Edouard Philippe canceling his appearance at his centrist party's final rally Friday night.
A terrorism probe was opened by the Paris prosecutor's office, which has jurisdiction over all terror cases in the country. Castaner was on his way to Lyon.
"I was working, serving customers, and all of a sudden there was a huge 'boom'," said Omar Ghezza, a baker who works nearby.
"We thought it had something to do with renovation work. But in fact it was an abandoned package," he said.