Police in Kasama district of Northern province have arrested 15 PF cardres.
The PF cardres earlier Saturday morning stoned the convey of NDC consultant Chishimba Kambwili.
Dr. Kambwili is in the northern province on a campaign trial.
NDC National Chairperson for Defence and security Menyani Zulu has condemned the cowardice behavior of PF Cadres.
Mr. Zulu has further hailed state police for arresting the unruly PF members.