Men of the Nigerian Police Force and the Nigeria Security and Civil Defence Corps (NSCDC) clashed at the venue of the primary election of the All Progressives Congress (APC) in Ondo state.
Gunshots released during the incident almost led to a disruption of the exercise, which had been going on without any hitch since around 1pm when the process began.
Delegates, party officials, and journalists scuttled to safety, while the security team at the International Conference Center of The Dome, venue of exercise, surrounded the ballot boxes.
However, normalcy was restored when information went round that supremacy battle between security agencies was behind the incident.
There are about 3,000 delegates partaking in process.
Twenty-four aspirants are seeking the ticket of the party ahead of the November 26 election.
The alleged attempt to impose a candidate sparked crisis, but the leadership of the party intervened, and constituted a fresh convention committee.