Twelve people are now confirmed to have died in the collapse of a six-storey building in Nairobi, with a further 120 people taken to hospital.

The latest death toll was confirmed by Kenyan interior minister Joseph Nkaissery following the disaster that is thought to be caused by heavy rain.

Rescuers said they could hear the voices of five people trapped in the collapsed building, but warned that it was going to be difficult to remove the concrete slabs using heavy machinery without endangering those buried in the rubble.

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Credit: PA Photos

Earlier, the National Youth Service and firefighters removed stones by hand and crowds cheered as a child was removed from the rubble.

President Uhuru Kenyatta visited the scene on Friday night and ordered the arrest of the owners of the building which had been condemned by the authorities. The Kenya Red Cross said up to 150 building units and adjacent homes were affected.

Jacob Kiruma, who said he lived in the house adjacent to the one that collapsed, said the building was constructed "shoddily."

The structure had been built in less than five months and the 126 single rooms were quickly occupied at a rent of 35 US dollars a month, Mr Kiruma said.

Kenyan police officers and Kenyan National Youth Servicemen work at the site of a building collapse in Nairobi Credit: PA Photos

Area legislator Stephen Kariuki said this was the second building to collapse in a year. He blamed the county government of failing to follow through with demolitions of buildings that were identified as unfit for human habitation.