Eight people were killed and at least two more are believed to be trapped under rubble after a building in Ivory Coast's commercial capital of Abidjan collapsed on workers who were demolishing it, a senior city official said on Thursday.

The accident occurred on Wednesday in Abidjan's Attecoube district as workers were knocking down a condemned building built in an area at risk of flooding and landslides.

"The ministry of construction hired a company for the building's demolition, but they didn't have any expertise. It went and hired around 20 young men to destroy the building by hand," the district's mayor, Paulin Claude Danho, told Reuters. Authorities have begun an investigation of the accident.

Officials from the construction ministry and the demolition company were not immediately reachable for comment.

Rescue efforts continued throughout the night, Danho said, and nine injured workers were rescued from the wreckage.

Ivory Coast, French-speaking West Africa's largest economy, is recovering from a decade of armed conflict and political crisis that ended in a 2011 civil war, and authorities are now trying to enforce long-neglected building and zoning codes.

Abidjan possesses some of West Africa's most advanced infrastructure. But the city of six million's poorer neighborhoods in particular suffer from heavy flooding during seasonal rains.