Democratic voters attend the caucus at the Wells Fargo Arena in Des Moines, Iowa, the United States, Feb. 3, 2020. Iowa, a state in the Midwestern United States, is holding Democratic and Republican caucuses Monday night, kicking off the 2020 U.S. presidential primary. (Xinhua/Li Muzi)

Pete Buttigieg, former mayor of South Bend, Indiana, and U.S. Senator Bernie Sanders are leading in the first set of Iowa Democratic caucus results released Tuesday afternoon.

With 62 percent of Iowa precincts reporting, Buttigieg is leading with 26.9 percent, followed by Sanders standing at 25.1 percent.

Senator Elizabeth Warren and former U.S. Vice President Joe Biden, with 18.3 percent and 15.6 percent, respectively, round out the top four.

Senator Amy Klobuchar garners 12.6 percent. No other candidates register in double-digit support.

It's unclear when the full results will be released.

The partial results were announced almost a day after the Democratic caucuses in Iowa Monday night, the first nominating contest of the 2020 presidential primary.

An announcement of the results was delayed due to a "coding issue" in a mobile app used to collect data for the Democratic events, according to Iowa Democratic Party (IDP) Chair Troy Price.

"This was a coding error in one of the pieces on the backend, but the raw data, the data that has come in, is secure," Price told a press conference.

The state party official also apologized for the reporting of the Iowa caucus results, which has caused confusion and discontent.

"The reporting of the results and circumstances surrounding the 2020 Iowa Democratic Party caucuses were unacceptable," Price said. "As chair of the party, I apologize deeply for this."