Kenyan opposition leader Raila Odinga said protests against President William Ruto's government over the high cost of living went ahead on Monday as scheduled despite a police ban.
Security was tight, with riot police stationed at strategic points in Nairobi and patrolling the streets, while many shops were shut and train services from the capital's outskirts into the central business district were suspended.
Police clashed with stone-throwing demonstrators in Nairobi's largest slum Kibera, where protesters set tires on fire, defying a warning by the Inspector General of Police Japhet Koome who said Sunday that the rallies were "illegal" and would be banned.
"We have been restraining ourselves. We cannot do that any more. We are ready as the police force to maintain peace," Koome told reporters at a media briefing.
Despite the police ban, Odinga called Sunday on Kenyans to join what he has described as "the mother of all demonstrations".
"I want to tell Mr Ruto and the IG Koome that we are not going to be intimidated," he said. "We are not going to fear tear gas and police."
Odinga also accused Deputy President Rigathi Gachagua of orchestrating an operation to cause "mayhem" at Monday's rallies.
The situation was calmer elsewhere in the city on Monday, with a heavy police presence in neighborhoods where protests had taken place last week.
In a Twitter post, Odinga also called for protests on Thursday.
President Ruto, who is currently on a four-day trip to Germany and Belgium, has urged his rival to halt the action.
"I am telling Raila Odinga that if he has a problem with me, he should face me and stop terrorizing the country," he said Thursday.
"Stop paralyzing the businesses of mama mboga, matatu and other Kenyans," he said, referring to women stallholders and private minibus operators.
This report was sourced from Reuters and Agence France-Presse.