At least 14 people have been killed in a six-storey building collapse in the Kenyan capital amid torrential rainstorms, as rescue teams shift rubble in a desperate search for survivors.

Nairobi police said 121 people had been rescued and taken to various hospitals following the building collapse.

Kenya Red Cross, who along with police and other rescue services continued to search the piles of crumbled concrete rubble, said a total of 150 households had been affected.

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Two neighbouring buildings in the densely-populated and poor Huruma neighbourhood were declared unsafe on Saturday and are being evacuated.

It is not known how many people were in the building at the time of its collapse.

The six-storey building collapsed around 9:30pm on Friday following the heaviest downpours since the start of the rainy season, Kenya Red Cross spokeswoman Arnolda Shiundu said.

“We don’t know how many people are under the rubble, but we fear there are still several of them,” she said.

Pictures broadcast by local media showed soldiers, policemen and civilians searching through the rubble of the collapsed buildings for survivors.

In other separate incidents, two people drowned when their vehicle was swept away by storm waters in the capital’s industrial area, another person died in floods, and four were killed when a wall collapsed, police said.

Nairobi Deputy Governor Jonathan Mueke, who visited the scene of the destroyed building on Saturday morning, said an investigation would look into why the two-year old building had collapsed.

“The building went down during the heavy rains, but we still want to establish if all the procedures were followed when it was constructed,” he said.

Nairobi has been in the middle of a building boom for some years but the quality of materials used and speed of construction have sometimes been called into question.

The growing middle class has triggered an explosion in demand for housing and a rise in real estate prices in the east African capital.