COLUMBUS, Ohio — A federal appeals court blocked rules requiring precise completion of thousands of absentee ballots in swing state Ohio, but upheld other challenged election-law changes in a Tuesday ruling as legal and not unduly burdensome.

The three-judge panel of the 6th US Circuit Court of Appeals in Cincinnati rejected all but one element of a lower court’s decision that found the laws violate the Voting Rights Act and place an undue burden on voters. US District Judge Algenon Marbley had said the laws could harm black voters in particular. Judge Damon Keith dissented in part.

The ruling affirmed Marbley’s rejection of absentee-ballot requirements for birthdate and address entries as presenting an undue burden on voters, saying Ohio could provide no justification for its precise standard. At the same time, the court reversed Marbley on other changes, saying they were not burdensome and didn’t disparately affect minorities.

At issue in the case were several changes on absentee and provisional ballot requirements Ohio’s Republican-led Legislature passed in 2014.

The panel’s ruling blocks Ohio from requiring the full and accurate completion of absentee-ballot forms before otherwise qualified voters’ ballots can be counted. It lets stand provisions that reduced the time voters could cure errors and prohibited poll worker assistance.

Advocates for the homeless and the Ohio Democratic Party sued Ohio’s Republican elections chief over the laws and procedures, saying they created hurdles for voters, particularly minorities. They pointed to instances of invalid ballots being counted and valid ballots being tossed as a result of the laws.

Attorneys for the state, which voted for Democrat Barack Obama in the last two presidential elections and for Republican George W. Bush in the two elections before those, said the challenged laws were reasonable and nondiscriminatory and imposed a minimal burden on voters.