Armed security forces have formed a tight cordon around the Cameroon football federation offices in Yaounde after disappointed fans threatened to ransack them following an ambarrassing defeat for the national team.

Cameroon's Indomitable Lions, three-times winners of the African Nations Cup, are in danger of missing out on a place at the next finals in South Africa after losing 2-0 to the tiny Cape Verde Islands in Praia on Saturday in the first leg of the final round of qualifiers.

Angry fans demonstrated outside the offices after the defeat, leading to the deployment of police and military personnel.

"A new visitor to this country may have thought we were at war or facing an invasion," said Martin Ndzinga who lives next to the offices in the Tsinga neighbourhood.

The unexpected defeat, the latest disappointment for a side also hit by the decision of captain Samuel Eto'o to boycott what he described as an amateurish team, has consumed the airwaves across the central African country.

"I'm very disappointed by the defeat of the Indomitable Lions. Cameroon does not merit this, not at all," local football coach Kisito Eloundou said.

"It is as a reason of poor preparation and the poor spirit in the team."

But under fire coach Denis Lavagne said there was still a home leg to be played.

"I think we can win that with a big score. We are in a difficult situation but everything is still possible," he told state radio.

Cameroon, who host the Cape Verdians on October 13, missed out on the last Nations Cup in a mini crisis for the country who have long been one of the dominant forces in African football.

They were the first Africa country to reach the World Cup quarter-finals and won Olympic gold in Sydney in 2000.