With a crowd of Occupy Wall Street protesters gathered on the sidewalk, Newt Gingrich skipped an appearance at his campaign headquarters in New Hampshire, where about 100 volunteers and supporters waited for him on the eve of primary day.

His campaign’s security team pulled the plug on the event after determining that the front and back entrances to the office were unsafe for Mr. Gingrich and his wife to enter, said R.C. Hammond, the campaign spokesman. The disappointed volunteers were scheduled to join Mr. Gingrich later in the evening at The Draft sports bar in Concord, where he planned to watch the college football championship game.

Mr. Hammond, who piped in by speakerphone to a press bus, declined to say why the security team made the decision. The protesters waved signs and chanted, supporting two competing candidates in the Republican primary: Ron Paul and an individual named Vermin Supreme, who wore a rubber boot on his head and danced while speaking through a megaphone.

Later, Gingrich told Fox News' Sean Hannity that "We decided that it wasn't worth risking some kind of big confrontation."