Jubilee Party's candidate in the Kibra by-election McDonald Mariga was on Saturday forced to flee a group of irate youth who pelted his convoy with stones and attempted to deflate the tyres of his vehicle after a campaign rally turned ugly.
The retired Kenyan international was unhurt in the incident but reported the matter to the police.
Meanwhile, Kikuyu MP Kimani Ichungwah has claimed - without providing evidence - that the violence was orchestrated by 'cowards' allied to ODM.
"This is what ODM was calling for when they called for demonstrations this week. They believe that only violence can activate their base. Get an agenda to run on other than demos and violence," Ichungwah wrote on Twitter.
Last week ODM accused the Jubilee Party of plotting to rig the mini-poll.
The opposition party had also threatened to call for demonstrations if the Independent Electoral and Boundary Commission (IEBC) does not avail the voter register which will be used in the election.
Besides Mariga, ODM's Bernard Okoth, ANC's Eluid Owalo and Ford Kenya's Hamisi Butichi are considered front runners in the by-elections slated for November 7.