Was this the most awkward opening to any US election debate?

Ben Carson was left waiting on the side of the stage in New Hampshire for what seemed like an age, as his Republican rivals for the White House gave him consoling pats on the shoulder.

It was not the only moment of unscripted drama - Donald Trump, who leads the polls in the state, was booed for telling Jeb Bush to be quiet.

Watch these two incidents plus other key moments at the debate, four days before voters in New Hampshire pick their presidential candidates.

Video by Olivia Lace-Evans