Nairobi: Around 2,000 Kenyans marched towards the election board offices in the city of Kisumu on Tuesday, witnesses said, responding to a call from opposition leader Raila Odinga for protests against an imminent election.
Odinga is boycotting Thursday's repeat presidential ballot.
He says the contest, against incumbent President Uhuru Kenyatta, will not be free and fair because the election board has not made sufficient reforms, and has called on his supporters to ensure it does not take place.
"All we know is that there will be no elections. As to how this will be done, we are waiting for the big announcement by Baba (Odinga) tomorrow," said one demonstrator, market trader James Ouma.
The government and the election board have said the vote will go ahead irrespective of whether Odinga contests it.
Kenyatta officially won their first head-to-head on August 8 by 1.4 million votes, but the Supreme Court annulled that vote on September 1 over procedural irregularities.
The ensuing political stand-off has blunted growth in East Africa's richest economy, and the risk of confrontations has raised security fears in a nation valued for its stability and relative freedom in a region roiled by conflict.
The protesters in Kisumu, an Odinga stronghold, waved branches and blew whistles as they marched.
After the Supreme Court ruling, Odinga's team presented a list of demands to the election board.
Some have been met - opposition monitors will now have access to the board's computers as results come in, a key official has gone on an extended holiday, and results will not be transmitted without a copy of a paper form from tallying centres.
The board said it was impossible to meet other demands - such as changing the technology provider - in the short time frame allotted for new elections.
The Kenyan constitution said fresh elections must be held within 60 days of nullified ones.