Royedar said they had registered 4,628 complaints, of which 1,700 were discarded, while 1,600 others would be looked into. Votes associated with them will be "quarantined," he said.
The preliminary results of the September 28 vote are expected on Saturday.
The election commission spokesman said they would finish transferring voters’ biometric data to the national register later tonight, which will allow the commission to unveil initial results.
"Today all the biometrics will be entered into the voting system, which will allow for the preliminary results to be announced," Abdul Aziz Ibrahimi said.
Afghanistan turned to biometrics to avoid ballot stuffing after election fraud complaints marred the 2014 vote. This year’s election saw the same frontrunners declare their victory, Ashraf Ghani and Abdullah Abdullah.
Another presidential candidate, Rahmatullah Nabil, said at the press conference that his campaign had observed instances of vote-rigging and would raise the issue with the United Nations.