Republican officials in Alabama staunchly defended their party’s Senate nominee, Roy S. Moore, after a report that he had made sexual advances toward four teenage girls when he was in his 30s.

The Washington Post reported that, in early 1979, Mr. Moore, then a district attorney and later the chief justice of the state Supreme Court, had approached a 14-year-old, eventually kissing her, undressing her, touching her over her bra and underpants, and guiding her hand to touch him over his underwear.

The paper found three other women who said they had been pursued by Mr. Moore around the same time, when they were between 16 and 18 years old. The Post interviewed more than 30 people in reporting its account.

Mr. Moore told The Post that the allegations were “completely false and are a desperate political attack by the National Democrat Party and the Washington Post on this campaign.” He is set to face Doug Jones, a Democrat, in a special election next month.