Problems with a mobile app appeared to force a delay in reporting the results of the Iowa caucuses on Monday, leaving the campaigns, voters and the media in election limbo and pressing for an explanation.
An Iowa Democratic Party official pointed to "inconsistencies in the reporting" of the results and said "quality control" efforts were holding up the results.
The official stressed that delay was not caused by a "hack or an intrusion".
But other caucus organisers put the blame squarely on a new technology used to report results from caucus meetings across the state.
Glitches with a new mobile app caused confusion, they said, and some caucus organisers were forced to call in results for the state party to record manually, introducing human error and delays.
Des Moines County Democratic chair Tom Courtney said he heard that in precincts across his county, including his own, the mobile app was "a mess".
Precinct leaders were instead phoning in their results to the Democratic Party headquarters, and "they weren't answering the phones", Mr Courtney said.
The problems were an embarrassment for a state that has long sought to protect its prized status as the first contest in presidential primaries and the nation's first vetter of candidates.
The Iowa Democratic Party pressed forward with the new reporting system amid warnings about the possibility of hacking and glitches.
Party officials said they took numerous security precautions and maintained that any errors would be easily correctable because of backups and a paper trail.
But the apps were barely working Monday night, according to a person involved in processing the data who requested anonymity to discuss the party's internal system.
That forced party aides to record results from the precincts via phone and enter them manually into a database. Officials were left using photos of results to validate results and ensure accuracy.
US Senator from Vermont Bernie Sanders addresses supporters during the Big Game Watch Party at Ingersoll Tap, a bar in Des Moines, Iowa. Source: EPA
"We found inconsistencies in the reporting of three sets of results," the party said in a statement.
"This is simply a reporting issue, the app did not go down and this is not a hack or an intrusion. The underlying data and paper trail is sound and will simply take time to further report the results."
