Mike Huckabee and Barack Obama have won the Iowa caucuses - the first nominating contest of the 2008 US presidential election.

Mr Huckabee won for the Republicans, defeating Mitt Romney.

At the Democratic caucuses, Mr Obama won by a clear margin, defeating John Edwards, who edged Hillary Clinton into third place.

The Iowa caucuses can give big boosts to candidates' campaigns. The next contest is on Tuesday in New Hampshire.