Motorists have been warned to avoid Waiyaki Way in the Gitaru area after armed youths reportedly blocked both the main highway and the diversion to Kikuyu.
According to eyewitness reports, the group is demanding Sh500 from each vehicle to allow passage.
Police said they have deployed a team to address the issue.
Police said a gang had taken advantage of an ongoing construction at the site to erect an illegal roadblock to demand money.
A number of motorists complained of harassment and extortion before a team of police rushed to the scene.
Police commanders in Kiambu have pledged to add more police at the site to help manage the traffic flow amid the construction works.
“The area is clear now. There were some elements who were disturbing traffic flow, but we have a team on the ground now,” Kiambu police boss Doris Mugambi said.
