Donald Trump has won the Republican presidential primary in Mississippi, edging out Texas senator Ted Cruz to post his 13th state victory of the 2016 White House race.
The billionaire businessman extends his lead for the highly-contested Republican nomination amid a growing outcry by party elites against his unorthodox candidacy.
Heading into Tuesday's contests, Mr Trump led the Republican field with 384 delegates, followed by Mr Cruz with 300, Marco Rubio with 151 and John Kasich with 37. Winning the GOP nomination requires 1,237 delegates.
Earlier, Democratic front-runner Hillary Clinton won her party's Mississippi primary, riding a continuing wave of support from black voters in Southern states to claim her latest victory over rival Bernie Sanders.
With 36 delegates at stake, the former US secretary of state and wife of former president Bill Clinton is assured of picking up at least 21.
Entering the contests, she held a 196-delegate lead over Mr Sanders based on the results from primaries and caucuses. But Mr Sanders is counting on winning several upcoming states in a bid to recapture momentum.
Mrs Clinton's lead is even bigger when including superdelegates, the party leaders who can support any candidate they wish. She now has at least 1,155. Mr Sanders has at least 502. It takes 2,383 to win.