Fans react while watching a broadcast of the 2021 Africa Cup of Nations soccer match between Ivory Coast and Algeria, in Abidjan, Ivory Coast, 20 January 2022. EPA-EFE/LEGNAN KOULA 
Images shared on social media, which Reuters could not immediately authenticate, showed screaming fans being crushed at an entrance gate.
The Confederation of African Football (CAF), the continent's soccer government body, said in a statement that it was investigating.
"CAF is currently investigating the situation and trying to get more details on what transpired. We are in constant communication with Cameroon government and the Local Organising Committee," it said.
Following a low turnout in the first round games at brand new stadiums built for the continent's premier men's soccer tournament, Cameroon authorities have thrown open stadium gates, organised mass transport and given out free tickets to lure fans.
Cameroon beat 10-man Comoros Islands 2-1 to advance to the quarter-finals.
(Reporting by Josiane Kouagheu; writing by Bate Felix; editing by Richard Pullin and Nick Macfie)