PHOENIX/RENO, Nevada, Nov 9 (Reuters) - Arizona and Nevada security officials remained on high alert on Wednesday for election-related protests and allegations of voter fraud, as they prepared for days of ballot counting to determine final results in key races for governor and U.S. Senate. Election officials in Maricopa County, Arizona's most populous, said it could take until at least Friday to tally all votes. About 400,000 votes in Maricopa County remain to be counted, election officials said. The race for governor and U.S. Senate remained uncalled on Wednesday, with about 70% of votes tallied. Jamie Rodriguez, the interim registrar of voters in Washoe County, Nevada, said during the state's primary season her staff was harassed by people convinced of election fraud.

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