By Jarrett Renshaw and Ginger Gibson

DES MOINES, Iowa (Reuters) – The Democratic Party’s effort to choose an election challenger to Donald Trump got off to a chaotic start in Iowa, with officials blaming “inconsistencies” for an indefinite delay in the state’s caucus results and the president gloating over his rivals’ misfortune.

Long lines and big crowds were reported in some of the more than 1,600 schools, community centers and other locations on Monday night and problems with a new mobile app designed to report the vote forced state party officials to verify the data by other means.

Some Democratic candidates left for New Hampshire, which hosts the next nominating contest on Feb. 11, without a winner announced in Iowa. The chaos was likely to increase criticism from Democrats who have long complained the rural state with a largely white population has an outsized role in determining the presidential candidate.

Shortly after midnight, Iowa Democratic Party Chairman Troy Price told reporters to expect results later on Tuesday in the state, the first to hold a nominating contest.

The party said it had to make “quality checks” after finding “inconsistencies” in the reporting of the data from caucus sites, sparking frustration among Democrats and criticism from Republicans.

Trump, a Republican, mocked the Democrats, calling the caucus confusion an “unmitigated disaster” in a Twitter post on Tuesday. “Nothing works, just like they ran the Country.”

The delay prompted two leading candidates in the Iowa race, U.S. Senator Bernie Sanders and former South Bend, Indiana, mayor Pete Buttigieg, to release their own tallies.

It was unclear when official results would be released.

Some local officials reported having trouble using the mobile app to report results, but when they turned to the traditional method – the telephone – they were put on hold and could not get through.

“We haven’t had that problem before that I know of. Normally we’ve called it in and got right through,” said Donna Crum, chair of the Democratic party in Mills County, Iowa.

Iowa Democratic Party officials said they were confident in their ability to ensure accurate results, citing a paper trail to validate the votes.

INAUSPICIOUS START

It was an inauspicious beginning for Democrats as the party’s 11 contenders began the state-by-state battle to pick a Democratic nominee to face Trump in the Nov. 3 election.

But Republicans in Iowa have their own history of chaos. On the night of the party’s 2012 caucuses, Mitt Romney was declared to have won by eight votes. But the party said two weeks later that Rick Santorum had won by a 34-vote margin. Romney went on to be the nominee.

“Every second that passes undermines the process a little bit,” said Roger Lau, campaign manager for U.S. Senator Elizabeth Warren.

A source in Buttigieg’s campaign said the delay would “delegitimize” the win and dampen the immediate benefits of a strong night. Former U.S. Vice President Joe Biden’s general counsel, Dana Remus, told state party officials in a letter there were widespread failures in the party’s system of reporting results.

After more than a year of campaigning and more than $800 million in spending, the results in Iowa were expected to begin to provide answers for a party desperately trying to figure out how to beat the businessman-turned-president.

Voters had to choose whether to back someone with appeal to independents and disaffected Republicans, like moderates Biden, Buttigieg and Senator Amy Klobuchar of neighboring Minnesota, or someone who energizes the party’s liberal base and brings out new voters, like progressives Sanders and Warren.

DECLARING VICTORY

With no results to celebrate or mourn, the candidates spun their own upbeat view of the outcome. The Sanders campaign released what it said were its internal numbers collected at 40% of precincts, showing him in first, ahead of Buttigieg, Warren and Biden in fourth place.

“I have a strong feeling that at some point the results will be announced, and when those results are announced I have a good feeling we’re going to be doing very, very well here in Iowa,” Sanders told cheering supporters.

Buttigieg told his supporters in Iowa that “we don’t know the results” but was looking ahead to the New Hampshire contest.

“By all indications, we are going to New Hampshire victorious,” he said.

Several of the candidates, including Biden, Klobuchar and Warren, headed to New Hampshire immediately after the caucuses. Sanders planned to fly there on Tuesday morning.

“Of course we don’t know the results yet – minor problem – but we know we did incredibly well,” Klobuchar told supporters at the Manchester, New Hampshire, airport.

At the caucus sites in Iowa, voters had gathered in groups by candidate preference in a public display of support. If a candidate did not attract 15% of voters, the total needed to be considered viable, that candidates’ supporters were released to back another contender, leading to a further round of persuasion.

Even if one candidate eventually wins by a commanding margin in Iowa, Democrats may still lack clear answers as the race moves on to the other three early voting states of New Hampshire, Nevada and South Carolina later in February.

Whoever remains in the race by Super Tuesday on March 3, when 15 states and territories vote, will also confront billionaire former New York Mayor Michael Bloomberg, who is skipping the early states in favor of focusing on states rich in delegates to the Democratic National Convention in July.

(Reporting by Trevor Hunnicutt, Joseph Ax, Tim Reid, Simon Lewis, Jarrett Renshaw and Ginger Gibson; Writing by John Whitesides and Doina Chiacu; Editing by Howard Goller and Giles Elgood)