It happened at Demba Diop stadium in the capital, Dakar, at the end of the League Cup final between Stade de Mbour and Union Sportive Ouakam.
Fighting started between rival fans and police responded by using tear gas, which led to panic, a stampede, and the wall collapse.
Some fans were throwing projectiles including stones at others.
Pictures circulating online appear to show people scrambling over a low wall amid clouds of gas.
Local news agency APS reported...