Several people were wounded in the gunfight on Wednesday, David Mafani Namange told AFP, describing what happened as “sporadic incidents.”
“The security forces rapidly intervened and an investigation is under way to determine who is responsible,” he said.
Earlier Thursday, a senior military officer said separatists had “attacked several districts in Buea.”
The gunfight “happened after the Malian squad had finished training — it did not have an impact on the training session,” he told AFP by telephone.
Also Wednesday, an opposition senator was found shot dead in the region, according to his party and an official.
Lawmaker Henry Kemende of the Social Democratic Front (SDF), one of Cameroon’s main opposition parties, had been shot several times in the chest, according to the SDF’s vice president, Joshua Osih.
No one claimed responsibility for the killing, but Osih blamed separatists.
Several SDF leaders have been targeted previously, including John Fru Ndi, the party’s president, a runner-up several times in elections won by President Paul Biya, 88, who has ruled the country with an iron grip for nearly 40 years.
Biya has been accused of repressing dissent in the English-speaking areas as well as clamping down hard on political opponents.
Describing Wednesday’s violence, a human rights lawyer, Agbor Balla, told AFP: “There were heavy exchanges of fire between troops and separatists.”
Speaking by telephone, he added: “Panic grew as the separatists moved towards the town centre.”
Balla, who heads an NGO called the Centre for Human Rights and Democracy in Africa, said one person “wearing civilian clothes” died in the exchange, but this toll was not immediately confirmed by other sources.
Buea is the capital of the Southwest Region, which with the adjacent Northwest Region has been rocked by violence since 2017, when anglophone militants declared independence from the majority French-speaking country.
The central government in Yaounde responded with a crackdown.
Both the separatists and government forces have been accused of atrocities in the fighting, which has claimed more than 3,000 lives and forced over 700,000 to flee their homes.
Armed groups are regularly accused of abducting, killing or injuring civilians whom they accuse of “collaborating” with Cameroonian authorities.
Armed groups had warned before the start of AFCON last Sunday that they planned to disrupt the month-long tournament.
Teams in Group F — Tunisia, Mali, Mauritania and Gambia — train in Buea and play in the coastal resort of Limbe.
English speakers account for nearly a fifth of Cameroon’s population of 24 million, who are majority French-speaking.
Their presence is a legacy of the colonial era in western Africa.
The former German possession of Cameroon was partitioned after World War I between Britain and France.
In 1961, part of the British territory, the Southern Cameroons, joined Cameroon after it gained independence from France.
The anglophone separatists call their entity the Federal Republic of Ambazonia, from the Ambas Bay on the coastline. It is not recognised internationally.