Vote counting has kicked off in Kibra constituency after a day of voting that was marred by chaos in some polling stations.
The polling stations were closed by 6pm.
A total of 24 candidates are battling for the 118,658 votes.
Results from polling stations are being transmitted manually to the tallying centre, acting IEBC CEO Hussein Marjan told the Nation.
The by-election follows the death of MP Ken Okoth after he succumbed to cancer in July.
Security was beefed up around various parts of Kibra as constituents cast ballots.
Officers from the GSU and the regular police were on standby manning the hotly contested seat in an exercise that was marred by claims of voter bribery and intimidation.