Supporters and police clashed before host nation Equatorial Guinea's second game at the Africa Cup of Nations.
Fans threw stones and bottles outside the stadium in Bata, with police responding by firing smoke grenades.
The violence, involving hundreds of fans, occurred as supporters were trying to enter the ground through a single entrance before the match against Burkina Faso began.
Some supporters reportedly did not have tickets for the game, which ended 0-0.
Fans have faced delays getting into other venues being used in the tournament, with two group matches played back-to-back at a single stadium each night.
Riot police and fans also scuffled before the first games in the city of Ebebiyin on Sunday.
|BBC Sport's Steve Crossman at the Bata Stadium in Equatorial Guinea|
|"Around 300 fans throwing bottles and stones outside the ground. Saw smoke grenades going off as more violent clashes affect Afcon 2015."|
Equatorial Guinea are hosting the tournament after Morocco's request to postpone the event because of the possible spread of Ebola was rejected by the Confederation of African Football (Caf) in November.
Supporters have their temperatures checked and are then asked to clean their hands with sanitising gel as they enter stadiums, which is also resulting in long queues.