Police operations have been on full alert since the issuing of writs earlier this week.
During Friday's nominations, the road blocks were set up in a way where vehicles moved in a one way in and one way out manner.
Officers on duty said so far, no major faults or incident in relations to the nominations have occurred.
Police are only controlling traffic at the main market area so supporters share a common a ground to campaign and support their candidates.
Police are also stationed along the main road leading up to the main Rigo District office for where only a controlled crowd can be able to enter with their candidate to pay and place their nominations.
Returning officer, Virgil Waisa said that so far since yesterday, four candidates have been nominated for the Rigo Open seat and more is expected in the upcoming days to the close of nominations next Tuesday.
Police will be on high alert to disrupt any activities short of being legal and to deliver a safe, free and fair election for the people of Rigo and Central Province.