CLEVELAND (AP) _ A federal judge on Wednesday struck down a first-of-its-kind voting rule that required naturalized citizens in Ohio to provide proof of their citizenship if challenged by a poll worker.

A group of naturalized citizens, backed by the state chapter of the American Civil Liberties Union, sued in August, alleging the law singled out one group of citizens and placed an unfair burden on them.

Secretary of State Ken Blackwell agreed that the rule was unconstitutional and did not challenge the lawsuit at a court hearing Wednesday.

Judge Christopher Boyko said the rule raised concerns of profiling and would have been detrimental to the voting rights of naturalized citizens.

``There can be no second-class American as far as any court is concerned,'' Boyko said. He asked that his decision be disseminated to other states.

Poll workers might have profiled voters based on their appearance, speech or manners, the judge said.

``How offensive it would be to be singled out by a poll worker,'' he said.

The law was believed to be the first of its kind in the country.

When the lawsuit was filed, Blackwell, the Republican candidate for governor, said the rule was unenforceable.

The rule was part of a voter identification law enacted this year that also would have required naturalized citizens to cast a provisional ballot if they could not show proof of citizenship upon a poll worker's request.

The voters would have had to go to a county elections board with documentation within 10 days to validate their ballots.

Laura Boustani of Cleveland, a naturalized citizen who emigrated from Lebanon in 1984, said the law was demeaning.

``I didn't think the country I chose would treat me this way,'' said Boustani, who was among the plaintiffs in the case.