He said that in the western counties of Homa Bay, Kisumu, Migori and Siaya -- all opposition strongholds -- the electoral commission would hold repeat elections on Saturday.
"We have faced and continue to face challenges which are largely security-related in certain electoral areas," said Chebukati.
"The commission has postponed elections in those areas to Saturday 28th October this week."
Chebukati said that heavy rains had also impacted voting in some areas.