The supporters of some political parties in Ahoada-west council area of rivers who accused the electoral body of bias in the conduct of the poll.
They alleged that the election materials sent to polling units were fake.
The supporters said INEC is not capable of conducting a free, fair and credible election in the area.
Their protest caused many voters to leave the polling units for fear of molestation, NAN reports.
INEC deputy director of voter education and publicity, Nick Dazang, denied the allegations, explaining that the result sheets were snatched and had been replaced.
He said: "How can INEC deploy fake election materials of which we are the custodian of our materials? What happened in Ahoada-West is that some result sheets were snatched and from available report, the result sheets have been replaced.
"INEC cannot deploy fake result sheets. It is like saying Central Bank of Nigeria (CBN) is producing fake currency. Is this possible? he asked."
Meanwhile, it was gathered that sounds of gunshots rented the air in Gokana, Eleme and Tai Local Government Areas of the state.
According to The Cable, the peaceful conduct witnessed in the early hours of the election process is fizzling out as people were seen running for cover amid sporadic shootings.