At least nine people are reported to have died in a building collapse in Nairobi in Kenya. Rescuers are contining efforts to reach many others trapped inside the rubble.A local TV channel said around 200 people had been injured. One hospital in the city reported it had received scores of casualties. People in the street joined rescue workers, pulling chunks of concrete away and helping victims to safety. Heavy construction equipment has been brought to the scene to remove large pieces of wreckage. It is not yet known what caused the collapse of the building in the centre of the Kenya capital but it was under construction. Workers were said to be in the process of installing new floors. One witness said the ground shook like an earthquake, reminding him of a tremor which struck the region in December.