Jubilee Party campaigns in Mandera turned chaotic early Saturday after two rival camps clashed at Moi stadium ahead of a rally led by President Uhuru Kenyatta.
The two camps, Jubilee supporters and those from the Economic Freedom Party (EFP), hurled stones at each other.
EFP supporters were dressed in blue colours while those from Jubilee were in red.
Calm was restored in the stadium before the president and his team from Nairobi arrived.
On Friday, Mandera Governor Ali Roba accused EFP leaders of planning to disrupt the rally and warned them against attending the rally.
Mr Roba is defending his seat on the Jubilee ticket and Hassan Noor Hassan is the EFP nominee.