City election officials said today that 817 voters in upper Manoa who requested absentee ballots for the general election were mailed two envelopes with ballots in them this week.

City Clerk Bernie Mau and chief elections officer Glen Takahashi apologized for the error, which was blamed on a mechanical glitch with the vendor, but stressed that they are confident enough safeguards exist in the system to prevent anyone from voting twice.

They said they are also sure the problem was confined to the 5th precinct of the 23rd House district, which votes out of Manoa Elementary School.

Officials learned of the problem when they received more than two dozen voters who had received two ballots in the mail. They then contacted the vendor, Hagadone Printing Co.

Oahu election officials began mailing out absentee ballots on Monday.

Those mailed two ballots were registered voters with the surnames starting with the letters M through Z, and had requested absentee ballot early.

The 817 voters are being asked to destroy the double ballots. They will receive new, distinguishable ballots in the mail next week, Takahashi said.

The source of the glitch was with Hagadone, which has the contract to print and mail the ballots this election cycle. A mechanized system erroneously inserted two ballots in the mail.

Mau said about 957 other voters in the district, with surnames starting in letters A through M, have not yet been mailed ballots.