A fuel tanker has overturned on Thika Superhighway causing a heavy snarl up on the busy road.
The accident happened between Roysambu and Githurai 45 estates, outbound.
Police officers have blocked the road on both ends with motorists being urged to look for alternative routes.
Officials from Energy and Petroleum Regulatory Authority (Epra) and Kenya Nation Highways Authority are shoring up safety efforts by police officers.
A statement from Kenha said: "KeNHA wishes to notify the public that a section of Thika Superhighway between Roysambu and Githurai (outbound traffic) has been temporarily closed after a petroleum tanker overturned, spilling fuel on the road."
Fuel was seen seeping out of the tanker. The accident also involved a lorry that also overturned.
Witnesses said there were attempts from a few to try to fetch the fuel.
"Saa hii uchumi ni mbaya, wangetuachia tuchote hii mafuta (The economy is bad, they should have let us get the fuel)," a witness said.
However, the police officers as well as the Kenya Defence Forces soldiers managed to control the crowd.
Water cannons were also used to keep the crowd at bay.
According to the police officers at the scene, once the spillage has been neutralized, there will be no effect on the residents.