A taskforce formed to spearhead the clean-up of Nairobi River on Friday oversaw the flattening of illegal structures put up on the river bed.
Mechanics working in garages near Grogan market watched helplessly as their shops were brought down by bulldozers. All structures erected within 30 meters either side of the river will be demolished.
The operation was backed by police officers and askaris from the city county inspectorate.
The market is the city's car repair center and parts shop. It is a source of income for mechanics, painters, food vendors as well as retail shops owners.
On Thursday, the Ministry of Environment together with the National Environmental Agency (Nema) launched a major cleanup of Nairobi River, promising to expand the cleanup to all the other affected rivers in Nairobi.
Environment Principal Secretary Charles Sunkuli said that a command centre, Nairobi River Restoration Command Center, has been set up for the cleaning exercise besides a multi-agency approach also being adopted by the government for the programme where government departments and the county government of Nairobi will be involved.
He warned individuals encroaching on rivers and riparian reserves that their structures will be demolished during the operation.
"We have today started with Nairobi River but this exercise will also be carried out in other rivers including Mathari, Mbagathi, Kirichwa kubwa and Kirichwa Ndogo among others.
"This is part of regeneration of Nairobi County which is a directive from President Uhuru Kenyatta," Sunkuli said on Thursday when he led a team in cleaning up Michuki Park next to the Globe Roundabout off Kijabe Street.