0626 GMT July 16, 2018
President Uhuru Kenyatta visited the wreck of the six-storey building on Saturday, where 10 people perished after concrete floors collapsed down on top of each other during torrential rainstorms on Friday.
The two-year-old building, home to more than over 150 families, had been condemned by building authorities but the order had been ignored.
"Ten bodies have been recovered, and we have 80 people who have been treated and discharged from hospital," Interior Minister Joseph Nkaissery told reporters amid the wreckage of the building, AFP reported on Saturday.
Seven other people died in floods elsewhere in Nairobi, including four killed when a wall collapsed.
"There is a lady in the building and her child who are alive, and all efforts are being made to rescue them, as well as other people still believed to be in the building," Nkaissery said.
But access for rescuers with larger machinery has been made difficult by the narrow and crowded streets.
One survivor was pulled from the huge pile of debris shortly after dawn, Kenya Red Cross said, some 10 hours after the building collapsed Friday night.
Pictures broadcast by local media showed soldiers, policemen and civilians searching through the rubble.
Kenyatta "braved the rainy and chilly weather" to visit densely-populated and poor Huruma neighbourhood, a statement from the presidency said.
He ordered police "take immediate action to identify and arrest owners of buildings who have ignored directives by the National Construction Authority", it said.
The building collapsed at around 9:30 pm (1830 GMT) Friday following some of the heaviest downpours since the start of the rainy season that caused flooding and landslides in many areas of the city.
Two neighboring buildings were declared unsafe and were evacuated.
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.
Nairobi has been in the midst 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.