Problems with a mobile app appeared to force a delay in reporting the results of the Iowa caucuses Monday, as the campaigns, voters and the media pressed party officials for an explanation and got few answers.

An Iowa Democratic Party official pointed to “quality control” as the source of the delays — but noted that about a quarter of the state’s nearly 1,700 precincts have reported their data already. The party also said the delay was not caused by a “hack or an intrusion.”

But other officials blamed technology. Des Moines County Democratic Chair Tom Courtney said he heard that in precincts across his county, including his own, a mobile app created for caucus organizers to report results to the party was “a mess.”

Precinct leaders were instead calling in their results to the Democratic Party headquarters, and “they weren’t answering the phones in Des Moines” because, Courtney speculated, they were mobbed with calls.

The apps were barely working, forcing party aides to record results from the precincts via phone and enter them manually into a database, according to a person involved in processing the data who requested anonymity to discuss the party’s internal process.

The slowdown came as the party attempted to report more data about the caucus than in years past — promising to release both a headcount of each candidates’ supporters and the delegate winners from each site.

“The integrity of the results is paramount,” Iowa Democratic Party spokeswoman Mandy McClure said in a statement. “We have experienced a delay in the results due to quality checks and the fact that the IDP is reporting out three data sets for the first time. What we know right now is that around 25% of precincts have reported, and early data indicates turnout is on pace for 2016.”

The problems were an embarrassment for a state party that has long sought to protect its prized status as the first contest in the primary race. The delay was certain to become fodder for caucus critics who call the process antiquated and exclusionary.

President Donald Trump’s campaign quickly seized on the issue to sow doubt about the validity of the results.

“Quality control = rigged?” Trump campaign manager Brad Parscale tweeted Monday evening, adding a emoji with furrowed brows.

Linn County Auditor Joel Miller, who ran a precinct in the Cedar Rapids suburb of Robins, said some app users may not have gotten the instructions on how to log into the system.

“If people didn’t know where to look for the PIN numbers or the precinct numbers, that could slow them down,” said Miller, who said he had no problem using the system to report his precinct’s figures and it worked fine.

Helen Grunewald, a precinct caucus chairwoman in Benton County, said she had been on hold with the party trying to report her results for a significant amount of time.

Earlier in the night, however, Iowa Democratic Party Chairman Troy Price said while there were some reports from precinct officials that they couldn’t log into the mobile app, a team of trouble-shooters was working to address any technical issues.

“We’ve had an app before but we’ve also had a hotline before, and folks have had the option to do that, and so we expect that we’ll be able to report the results in a timely manner this evening,” he said.

(AP)