At least 12 people have been killed in Burkina Faso in floods caused by torrential rainstorms, a rescue services official told AFP on Thursday.

Since June, "we have registered several disasters, mainly floods and strong winds, which left at least 12 people dead and 35 critically wounded, and affected more than 26,000 others", said Yipene Florent Bakouan of the west African nation's emergency services.

The dead had either drowned or been crushed under their collapsing homes.

With 40 percent of Burkina Faso's population of 19 million living beneath the poverty line, housing is often inadequate and prone to damage or collapse.

In the suburbs and shantytowns of Ouagadougou, around 9,900 people were left homeless. Two thousand of them were given shelter in schools, the spokesman said.

"We have also counted 2,577 damaged houses, while nearly 100 tons of grain have been lost, 237 granaries destroyed, 123 sheep and goats were put down and more than 630 poultry died," he added.

The authorities are concerned there will be no let-up in the flooding, with weather reports for the months ahead showing much higher rain levels than normal in most of the country, he said.