The Osun State governorship rerun witnessed a set back as voters were forced to flee a polling unit in Osogbo, as gunshots were being fired.
Calm was, however, restored as security officials immediately swung into action.
Prior to the shooting, security operatives had arrested three men for allegedly carrying charms and banned substances also in Osogbo.
Another man, a resident of the street where the polling units are situated, was dragged and teargassed.
He was allegedly taking pictures from his balcony.
The police also arrested another man perceived to be obstructing the voting process at another polling unit also in Osogbo.
Earlier, the Independent National Electoral Commission (INEC) also expressed concern over reports that some observers and journalists were being arrested and prevented from operating in some polling units in the Osun State governorship supplementary election.
The commission said this in a tweet, adding, however, that the issue was being taken up with the security agencies.