Voters were required to wear face masks and distance from others at some 3,100 polling places across Iran. Votes were cast in the provinces of East Azarbaijan, Isfahan, Ilam, Alborz, Zanjan, Khuzestan, Kurdistan, Kermanshah and Golestan.

Iranian interior minister Abdolreza Rahmani Fazlisaid said officials will examine how the safety protocols work Friday and make any necessary tweaks ahead of the presidential election next spring.

"If the coronavirus pandemic lingers on, we will have to consider special conditions, reservations, and requirements for the 2021 presidential elections," Fazli told reporters.

Friday's election will fill vacancies in Iran's 290-member parliament. More than 24 million people voted in the first parliamentary elections in February and the runoffs were originally scheduled for April before they were delayed.

Voting in Iran came one day after tech giant Microsoft said in a report that it found evidence Iran, Russia and China have all attempted this year to interfere in the U.S. presidential election.

Microsoft's report said hackers associated with the three nations have carried out cyberattacks hoping to mine information on President Donald Trump and Democratic nominee Joe Biden.

Tehran denied the accusation on Friday, countering that the United States has no ethical ground to stand on since it has long tried to disrupt foreign elections.