HONOLULU — Hawaii elections officials are reporting half of the ballots mailed to registered voters in the contest for Hawaii's vacant 1st Congressional District seat have been returned.

Office of Elections spokesman Rex Quidilla said Friday that an estimated 159,000 ballots have returned out of the 317,337 that were sent voters in the all-mail special election for the 1st Congressional District.

The ballot-return rate is much higher than the 13.3 percent who voted at traditional polling places in the 2002 race to fill a vacancy in the 2nd Congressional District.

The leading candidates are Democrats Ed Case and Colleen Hanabusa, and Republican Charles Djou.

Ballots must be received by the state by Saturday.