Uber drivers went offline and began a strike on Thursday to demand higher rates because of low profits.
Passengers trying to access the service found the message "0 hours online and 0 trip".
On Wednesday, the taxi-hailing firm said that starting today it would charge users a minimum fare of Sh300 for trips within Nairobi.
In a message to the drivers, the operator set the base fare at Sh100, a Sh42 charge for every kilometre and Sh3 for every minute a customer's pick-up is active.
But the protesting drivers want Uber to revert to fares of Sh60/km and Sh4 per minute, pending review of fares by a committee that is to be formed.
They are also demonstrating against the management's laxity towards effecting price changes.
A secretary to the digital association said Uber raised the fares as a tactic to water down the strike.
"I am sorry to disappoint you all, inside sources just confirmed the price increase is a tactic to water down the strike," the secretary said.
Some of the drivers said the prices were likely to be reverted to what they originally were.
They demanded that the new rates should be "put in white and black'.
Hitmen to go after 'traitors'
Some drivers warned that they will attack those who do not join the strike and that some areas in the city would be no-go zones.
"We had a very successful meeting [on] Thursday and Friday demos. There will be a team in Kitengela near the [boda boda] stage," a driver only known as Apollo wrote to colleagues.
"Don't dare [go to] Gateway Mall because the worst team will be waiting for the traitors both at the service lanes and the highway."
In the message seen by the Star, the driver said the decision was reached in a meeting attended by 90 per cent of its members.
"The airport team will be patrolling every terminal and the parking lots. Dare [go to] airport, the white pick-up belonging to KAA will be on your neck," he said.
Apollo said they will also be going round trying to identify vehicles with private insurance and impound them at Airport police station.
Another driver known as James Jaymoh cautioned those planning to hide during the strikes.
"Thursday and Friday will [see] the mother of all demos...take caution...we have sealed all the loopholes," he said.
He asked those unwilling to join the strike to remain at home instead of working.
"Please, if you won't be with the others, park and stay at home. We will no longer take any liability regarding attacks or damages. Please preach the word to everyone...whoever have ears should hear," he said.
Jaymoh said the protest will include digital onliners and boda bodas.
"[Whoever is thinking of taking advantage of the situation should take care. Hitmen will be all over monitoring [areas including] Kiambu, Kajiado, Rongai, Ngong town, Karen. Kikuyu and Ruaka. Please be with us or be at home," he said.
On February 23, Uber drivers marched to Parliament in a demand for rules for fair operation and the revision of rates.
The drivers wanted MPs to help them formulate a comprehensive set of rules and regulations for the industry to accommodate digital platforms and analog operators.
The taxi company launched its services in Nairobi in January 20 and has since branched into towns including Mombasa and Thika.