US election 2016: Rivals seek gains in four states

People in four US states are voting in the party contests to choose the candidates who will compete in November’s presidential election.

The biggest prize is Michigan where the front-runners – Donald Trump for the Republicans and Hillary Clinton for the Democrats – will seek to consolidate leads over their respective rivals.

Read more at: http://www.bbc.com/news/election-us-2016-35760148