Washington: Republican Donald Trump and Democrat Hillary Clinton each won their party primaries in Mississippi, US networks said Tuesday, cementing their frontrunner status in the White House nomination race.

‘Thank you Mississippi!’ tweeted the billionaire real estate mogul as results came in from the southern state.

John Kasich was projected to have taken second place in Mississippi, followed by Texas senator Ted Cruz and — far behind — Florida Senator Marco Rubio.

Clinton’s win in Mississippi adds to a string of victories over her party rival Bernie Sanders — and continues a winning streak in the southern United States where she has so far cornered the large African American vote.

Early results were also coming in from the northern state of Michigan, the other big prize in Tuesday’s primary contests, where the bulk of polling places close at 0200 GMT.

With 13 percent of precincts reporting, Trump took an early lead in the industrial state on 37.6 per cent, ahead of Kasich’s 27.5 per cent, while on the Democratic side Sanders had the narrowest of leads over Clinton, with 49.8 to 48.3 per cent according to US media.

Republican voters also have their say Tuesday in a primary in Idaho and a caucus in Hawaii.