Mombasa Governor Hassan Joho and former Nairobi Governor Mike Sonko clashed at a polling station on Tuesday when the voting exercise was coming to an end.
The two were moving around inspecting the voting process when they differed after they met at the Marycliff Primary school polling station.
Police intervened before the clash could escalate any further.
Sonko and his would-be running mate, Ali Mbogo came to Marycliff after they had bailed out Mvita UDA MP aspirant Omar Shallo who was detained at Makupa Police Station.
Joho who was at the polling station with other Azimio la Umoja leaders
Shallo was arrested alongside MCA aspirant Samir Bhalo for allegedly disrupting the electoral process at the Tudor Village Hall.
The two were arrested as police tried to calm residents supporting different camps, who were busy hurling stones at each other.
The chaos began after ODM and UDA supporters engaged in a physical confrontation at the station in Mombasa County.