'After a Lille goal, the Lille fans celebrated and huddled against a barrier that collapsed.
Lille had opened the scoring in the 15th minute through Fode Ballo-Toure.
The celebrations caused a fence separating the fans from the pitch to crumble under their weight.
AFP GETTYLille fans are treated after the collapse at Amiens
"The incident assessment reported 20 injured, of which three were transported to hospital", Lille confirmed.
Several supporters tumbled around 1.5 metres down to the side of the pitch and were crushed by fellow fans before emergency services rushed to the scene to tend to the injured.
Amiens said the stadium was successfully and peacefully evacuated.
Amiens' Stade de la Licorne is now undergoing renovation work, with one stand at the compact arena closed for refurbishment. One stand is closed for refurbishment, and repairs are also being carried out on the stadium's roof.