A low turnout could signal widespread dissatisfaction with Iran's clerical rulers and the system they preside over. Iranian officials usually release turnout figures a day after elections.
A range of crises has beset Iran in the past year, including widespread anti-government protests in November and U.S. sanctions piling pressure on the plunging economy.
In remarks from his office in Tehran, Ayatollah Ali Khamenei blamed the "negative propaganda" of Iran's enemies for trying to discourage people from voting in Friday's elections.
"Their media did not ignore the tiniest opportunity for discouraging people and resorting to the pretext of diseases and the virus," he said.
Iran reported its first case of the virus two days before the national polls, and six deaths from the illness since then. That's the highest death toll from the virus outside of China, where the outbreak first emerged a couple months ago.
Iran has confirmed 28 cases in total in at least four different cities, including the capital, Tehran, where some pharmacies have already run out of masks and hand sanitizer.
Schools were shut down in Tehran and four other cities for two days, starting Sunday, to prevent the spread of the virus. Authorities have also suspended football matches and stopped shows in movie theaters and other venues.
Officials across Iran encouraged people to vote in the days leading up to the election, even as concerns over the virus' spread began to rise.
Voters had limited options on Friday's ballot, as more than 7,000 potential candidates had been disqualified, most of them reformists and moderates. Among those disqualified were 90 sitting members of Iran's 290-seat Parliament who had wanted to run for re-election.
Iranian state TV on Saturday announced some partial results, indicating a strong showing by hard-liners in the capital.
On the eve of the vote, the Trump administration sanctioned five election officials and Secretary of State Mike Pompeo slammed the election as a "sham."
Meanwhile, authorities in Iran said they would begin disinfecting Tehran's metro, which is used by some 3 million people, to stymie the spread of the virus. The government has also closed down schools and religious seminaries in the holy city of Qom, where the virus first killed two elderly patients last week.
Iraq and Pakistan, which share borders with Iran, have taken preventive measures to limit the spread of the virus from Iranian travelers. Infected travelers from Iran already have been discovered in Lebanon and Canada.
Saudi Arabia has ordered anyone traveling from Iran to wait at least 14 days before entering the kingdom as it seeks to prevent the spread of the virus to the Muslim pilgrimage sites of Mecca and Medina.
Also on Sunday, Iranian Foreign Minister Mohammad Javad Zarif joked about shaking hands with his visiting Austrian counterpart Alexander Schallenberg and told reporters: "We have to shake hands with them, don't worry I don't have coronavirus."
Last week, Schallenberg said that he would travel to Tehran amid efforts by European countries to keep alive Iran's nuclear agreement with world powers. Regional tensions have steadily risen since the U.S. withdrew from the landmark deal.