At least 10 people have been injured by a freight train that crashed into homes in the Nairobi slum of Kibera.
The train derailed while passing through the slum - one of Africa's largest - on its way to Uganda.
Rescuers cleared space in the crowded settlement to bring in cranes to lift rolling stock and reach anyone who may have been trapped.
There had initially been fears that scores were trapped in their homes, but many residents were out at the time.
Local people suggested that they had left for church or gone back to their villages for Christmas.
The Red Cross, quoted by the Associated Press news agency, said seven people had been rescued and taken to hospital. Another three had slight injuries.
Fire department spokesman Johnson Mia said: "Most of them were crying out from the structures that were crushed and they couldn't move, but we managed to dig out and rescue them."
There are no reports of anyone else missing.
There were also reports that a tank containing flammable fuel was leaking on to the tracks.
Kibera is estimated to have a population of around 250,000.
Mr Kamau said residents had long been warned not to put up houses next to the railway line.
"We have always warned people against encroaching on the line," he was quoted as saying.