At least six people have died in a stampede outside a stadium hosting an Africa Cup of Nations soccer game in Cameroon, an official said Monday.

Naseri Paul Biya, governor of the central region of Cameroon, said there could be more casualties.

The stampede happened as crowds struggled to get access to Olembe Stadium in the Cameroon capital of Yaounde to watch the host country play Comoros Islands in a last-16 knockout game in Africa’s top football tournament.

Officials at the nearby Messassi hospital said they had received at least 40 injured people from the stampede.

“Some of the injured are in desperate condition,” said Olinga Prudence, a nurse. “We will have to evacuate them to a specialized hospital.”

Officials said around 50,000 people had tried to attend the match. The stadium has a capacity of 60,000, but it was not meant to be more than 80% full for the game due to restrictions on the size of the crowd because of the coronavirus pandemic.

Cameroon won the game 2-1 to reach the quarterfinals.