Sen. Bernie Sanders' campaign is reviewing results of the Iowa Democratic caucus precinct by precinct to ensure results were reported to the state party correctly.

The Vermont senator's Iowa spokesperson Iowa, Rania Batrice, said the campaign has found "some inconsistencies" and believes that there are probably more out there. The inconsistencies are "very likely are just human errors," she said.

Democrat Hillary Clinton became the official winner of the Democratic caucus after Iowa Democratic Party (IDP) released its final result on Tuesday. It showed Clinton winning just under four more state delegate equivalents than rival Sanders.

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In terms of percentages, the former secretary of state won 49.9 percent of delegates and the Vermont senator won 49.6 percent. There are 1,681 precincts.

Batrice said the campaign was alerted on the night of the caucus that some precinct chairs - who are responsible for relaying results to the party - were designated at the last minute or on the spot, and that the party was initially missing information from 90 precincts. That information was a red flag, and it led the Sanders team to decide to review the results since the race was so close, she said.

It will be several more days before the review is complete and the campaign will consider how to move forward from there.

In a statement, Iowa Democratic Party Communications Director Sam Lau noted that it is impossible to do a recount of the vote because people physically align in groups to indicate their preference and do not fill out paper ballots.

"Monday's caucuses were a unique event that involved more than 171,000 Iowans and their neighbors at a specific time and place, and thus they cannot be re-created or recounted," Lau said. "That being said, we are working with all campaigns on individual concerns they are bringing to us, and addressing them on a case-by-case basis. Just yesterday, we met with the Sanders campaign, [which] brought us a small amount of specific concerns, and the Clinton campaign has also asked us a small amount of questions. We will look into these concerns and reach out to our county party leadership with any questions."

While Clinton's camp has declared victory in the caucus, Sanders' campaign has characterized the election as a "virtual draw" and criticized the process of using coin tosses to settle ties.

In an editorial Thursday, the Des Moines Register said it was time for the Democratic Party to affirm the accuracy of the results "beyond a shadow of a doubt" and reassess the caucus process.

"The caucuses have become as antiquated and opaque as the smoke-filled rooms of yore," the editorial said. "Democrats should ask themselves: What do we want the Iowa caucus to be? How can we preserve its uniqueness while bringing more order? Does it become more like a straw poll or primary? How do we strike the balance between tradition and transparency? We have time to consider these questions. First, however, we need answers to what happened Monday night. The future of the first-in-the-nation caucuses demands it."

The editorial said the party should work with all campaigns to audit results, release raw vote totals, release a list of all coin flips and their outcomes, and then overhaul the entire caucus process.

CBS News Digital Political Journalists Hannah Fraser-Chanpong and Kylie Atwood contributed to this story.