The Independent Electoral Commission (IEC) said it remained committed to transparency and would deal with anyone who contravened the Electoral Code.
The IEC has received seven official objections regarding voter irregularities, which were under investigation.
On Wednesday, voters and politicians posted photos and videos on social media, complaining of possible voter fraud.
Some complained that voter boxes were being transported without police overseeing the process. Other voters said the ink marking could be removed easily and scanners were not working properly, with some people claiming they could vote twice.
IEC commissioner Mosotho Moepya said: “We are going to hold people accountable. It has never happened before. If it has happened, we will deal with it. We will leave no stone unturned.”