Apparent technology issues have held up results in the contest to pick a Democratic candidate to face Donald Trump.
On Monday, voters in Iowa flocked to more than 1,600 schools, libraries, and churches to select a Democrat to run against Donald Trump in November’s presidential election.
Yet “reporting issues” have delayed the results until Tuesday, with several candidates claiming victory.
Vermont Senator Bernie Sanders cited internal campaign data that placed him ahead of Pete Buttigieg, the former mayor of South Bend, Indiana.
Earlier, Mr Buttigieg had told supporters that “by all indications” his campaign was “going to New Hampshire victorious.” Another vote will be held in that state on Feb. 11.
For his part, President Trump mocked the problems, tweeting that “the only person that can claim a very big victory in Iowa last night is ‘Trump’.”
Iowa Democratic Party (IDP) spokeswoman Mandy McClure said officials had found “inconsistencies in the reporting of three sets of results” that was simply a “reporting issue” rather than a hack or intrusion.
She denied accusations that an app created to report results had gone down.
“The underlying data and paper trail is sound and will simply take time to further report the results,” she explained.
Local party chairman Troy Price added: “We are validating every piece of data we have against our paper trail. That system is taking longer than expected, but it’s in place to ensure we are eventually able to report results with full confidence.”
Rules on reporting were modified this year, with Iowa Democrats required to report three numbers to party headquarters, instead of just the final delegate totals.
Party officials at county level contradicted Ms McClure, blaming technology issues for the delay.
They said the app created for caucus organizers to report their results had malfunctioned, leaving precinct heads to call state party headquarters, whose phone lines became jammed.