A fence separating Lille fans from the pitch gave way as they surged forward to celebrate the goal against Amiens, a regional rival that has just been promoted to the top flight in French football.
Several tumbled about one and a half metres (five feet) and were crushed by other fans who fell on top of them. Injuries included head, chest and abdominal trauma, medical authorities said.
Referee Thomas Leonard suspended the match in the 16th minute as Red Cross and emergency workers rushed to help the injured. The fixture was later abandoned.
"It happened all of a sudden. I don't even know who scored. It just suddenly fell on me. I couldn't hear anything, I couldn't see anything and then the emergency workers took me away," said Georges Penel, a 21-year-old Lille fan who suffered injuries to his leg and back.
The prefecture of the Somme department gave a provisional toll of 29 hurt, five of them seriously. Among the injured were three minors, all in their teens, medical authorities said.
The incident happened when Lille's Fode Ballo-Toure ran towards the section of visiting fans after scoring the opening goal, prompting a surge that caused the barrier to give way.
Built in 1999, the Stade de la Licorne ("Stadium of the Unicorn") is the smallest of the 20 French Ligue 1 clubs, with a capacity of only 12,000.
Renovation work is taking place throughout the 2017-18 season, as newly promoted Amiens brings the ground up to a higher standard.
- 'Hardcore fans' -
The venue boasts an eye-catching, futuristic design with a transparent roof, which is being renovated. The seats are also being progressively replaced under the 7.5-million-euro ($8.9-million) scheme.
"The work is going to start in June and will be done stand by stand," local politician Alain Gest said last May.
The Amiens public prosecutor, Alexandre de Bosschere, said an investigation had been opened into "accidental injury", focusing on why the barrier gave way.
"We have put legal seals on the site (to bar access to it), and an assessment will be carried out in the next few days."
Amiens' president, Bernard Joannin, dismissed any idea that there were problems with the barrier.
"The police had warned us that there were 200 hardcore fans, really wound up, who were in the section set aside for Lille fans. They surged forward, chaotically, more than 500 people, against this barrier, which was in perfect condition."
Gest, in his comments in May, had suggested that upkeep of the stadium had been neglected by previous local administrations but was now "perfectly in line with regulations" and "up to standards for playing in Ligue 1".
A safety audit in 2016 had noted that the stadium roof presented "serious dangers", he said.
"This forced us to dismantle at the beginning of the year all the (roof) glass -- almost 2,000 glass plates per stand."
The official said the plates had to be replaced by "a rigid and transparent plastic material like those used at the stadiums of Le Havre and Nice".
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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