9 March 2016, USA: Hillary Clinton has won the Democratic primary in Mississippi, the first of four party contests being held.
The state contests 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 Mrs Clinton for the Democrats – will seek to consolidate leads over their respective rivals.
Both parties are also holding primaries in Mississippi on Tuesday.
In addition, the Republicans are voting in Idaho and Hawaii.
Billionaire businessman Mr Trump is well ahead in the all-important delegate count, but a poor debate performance and some recent losses to Texas Senator Ted Cruz have raised questions about the solidity of his lead.
Mr Trump is currently in the lead in Mississippi according to exit polling data, trailed by Mr Cruz.
After the previous round of voting on Saturday, Mr Trump, a New York property tycoon with no experience of elected office, won in Louisiana and Kentucky.
Ted Cruz was victorious in Kansas and Maine, while his Republican rival Marco Rubio won in Puerto Rico.
Analysts say Mr Cruz appears to be the only candidate who can stop Mr Trump, who has been fiercely criticised by the Republican establishment.