21.   It will be his first ever visit to Sarajevo and will involve unprecedented security.

22.   Liftoff was set for just after sunset amid unprecedented security to guard against terrorist attacks.

23.   Liftoff was set for just after sunset Tuesday amid unprecedented security to guard against terrorist attacks.

24.   Mrs. Rabin later addressed the crowd at the former Kings of Israel Square in Tel Aviv, where unprecedented security was in place.

25.   NASA waited as long as possible before halting the countdown, conducted amid unprecedented security.

26.   Officials promised unprecedented security at the Shubert Theatre, a smaller venue than the Shrine Auditorium where the show was originally scheduled.

27.   Officials promised unprecedented security at the Shubert Theatre.

28.   Officials promised unprecedented security at the Shubert, a smaller venue than the Shrine Auditorium where the show was originally scheduled.

29.   Putin visited Azerbaijan in January amid unprecedented security.

30.   Some participants were worried about safety, although officials said no threats had been received and that unprecedented security measures were in place at the Shrine.