US election: Trump dealt blow by Cruz in Iowa vote

                                 

 Texas Senator Ted Cruz has won the Iowa Republican caucuses, the first vote of the US 2016 presidential election.

"Tonight is a victory for courageous conservatives," he declared, to great applause, as he railed against Washington, lobbyists and the media.

He took 28% of the Republican vote, beating his rival, the once frontrunner Donald Trump, and Marco Rubio.

Votes in the Democratic race are still being counted, and some US media have declared it a dead heat.

With 95% of results confirmed, Hillary Clinton clung to the narrowest of leads over Bernie Sanders and told supporters she was "breathing a sigh of relief".

The former secretary of state and first lady stopped short of declaring victory, and her rival, a 74-year-old senator from Vermont, said it was a "virtual tie".