"During this time when we face an unprecedented public health crisis, to conduct an election tomorrow would force poll workers and voters to place themselves at an unacceptable health risk of contracting coronavirus," DeWine tweeted.
DeWine said Dr. Amy Action, director of the Ohio Department of Health, had signed the order to close all polling locations, and that Ohio Secretary of State Frank LaRose would seek a remedy through the courts to extend voting options to Ohioans.
Earlier on Monday, DeWine said he requested a court in the midwest state to grant delay of the state's Tuesday primary to June, but a Franklin County judge ruled in the evening that it would be a "terrible precedent" for a judge to change the date and rule 12 hours before the election takes place, according to local media reports.
Ohio is one of the four states set to vote on Tuesday. The other three -- Arizona, Florida and Illinois -- still plan to hold their primary elections on Tuesday, said the reports.
A number of U.S. states, including Louisiana, Georgia and Kentucky, have postponed their primary elections due to the COVID-19 outbreak. Wyoming Democratic Party Chair Joe Barbuto announced Friday that "the in-person portion" of their state's caucuses was "suspended due to growing concern" over the virus.
U.S. President Donald Trump on Monday advised people not to gather in groups of more than 10, one day after the U.S. Centers for Disease Control and Prevention recommended no gatherings with 50 people or more for the next eight weeks.
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