An unmanned train caused panic along the Nairobi-Ruiru railway on Wednesday evening as it sped towards Githurai.
Police said the train had stopped at the Makadara station awaiting to have wagons attached when the driver, who was in his cabin, realised the pressure was low and the brakes were not working.
"The driver and the engineer managed to get into another train at the scene and trailed the unmanned one while hooting from a distance to warn pedestrians," Nairobi police commander Japheth Koome said.
The engine began to roll forcing the crew to jump off and seek help.
Railway staff rolled a boulder on the track to stop the engine, but the train crushed the rock and continued down the slope.
RVR crew hopped into another train and followed the runaway engine, while hooting to alert other rail traffic.
They also called police from various stations along the railway line including Dandora and Mowlem, to caution rail users and avert an accident.
The runaway train came to a standstill after losing momentum at a slope at Njiru bridge, about 14 kilometers later at 6:45pm.
RVR had to cancel the evening train ride as railway crew pulled back the engine to undergo inspection and ascertain what went wrong.
Koome said no injuries or damage was caused to people or property.