KAMPALA—Ugandan opposition leader Bobi Wine and his party said on Tuesday that around 3,000 of his supporters had been detained or abducted by state agents since November, when protests flared over his arrest during a presidential election campaign. The police said they were investigating all reports of disappearances. They have previously said they arrested nearly 600 people in connection with the November unrest, and accused protesters of rioting and looting. Government spokesman Ofwono Opondo and President Yoweri Museveni’s spokesman Don Wanyama did not immediately answer telephone calls seeking comment on the assertions. Wine, who is also a pop star, on Monday filed a court challenge to the results of the Jan. 14 presidential election, which handed victory to Museveni, in power since 1986. Officials in Wine’s National Unity Platform (NUP) told a news conference that squads of state security personnel had appeared around Uganda in unmarked minivans and taken supporters …