U.S. media say presidential hopeful Senator Barack Obama has won the Democratic Party's nominating contest in the western state of Wyoming, beating out his rival, Senator Hillary Clinton.
With 91 percent of precincts reporting, Obama has 58 percent of the vote compared to Clinton's 41 percent.
The Wyoming caucuses offer only 12 delegates, but Obama's campaign could use the boost after losing three contests to Clinton earlier in the week.
Overall, the latest polls show the two virtually deadlocked in the battle for the Democratic Party presidential nomination.
Neither candidate is expected to receive a majority of the delegates in the remaining contests to clinch the nomination as Senator John McCain did in the Republican Party contest. That means the race could be decided by party leaders known as "super-delegates" who are free to vote as they wish at the party's convention in August.
Both candidates have taken a rare day off from the campaign trail.
Another Democratic primary will be held in the southern state of Mississippi on Tuesday. There are 33 delegates up for grabs in that contest.
Senator John McCain, having already clinched the Republican Party's nomination, is now campaigning for the November general election.
Some information for this report was provided by AP and Reuters.
