The phone number to report Iowa caucus results was posted on a fringe internet message board on Monday night along with encouragement to “clog the lines,” an indication that jammed phone lines that left some caucus managers on hold for hours may have in part been due to prank calls.

An Iowa Democratic Party official said the influx of calls to the reporting hotline included “supporters of President Trump who called to express their displeasure with the Democratic Party.” The party official’s comments were first reported late Wednesday by Bloomberg News.

Users on a politics-focused section of the fringe 4chan message board repeatedly posted the phone number for the Iowa Democratic Party, which was found by a simple Google search, both as screenshots and in plain text, alongside instructions.

"They have to call in the results now. Very long hold times being reported. Phone line being clogged," one user posted at about 11 p.m. ET on Monday, three hours after the caucuses began.

"Uh oh how unfortunate it would be for a bunch of mischief makers to start clogging the lines," responded another anonymous user, sarcastically.

Some users chimed in, posting alleged wait times on hold, imploring others to “clog the lines [and] make the call lads.”

Rob Sand, state auditor of Iowa, said he took results calls on Monday night as a volunteer and received an influx of calls that appeared to have been generated by a post on the internet.

“A lot of calls came in at a certain point where it was clear somebody had published the hotline number somewhere,” Sand said.

He cautioned that he could not speak for other people who were taking calls and said he did not get any calls that said they were from Trump supporters. He added that the system prevented people from reporting fake results.

He also said he was able to identify fake calls quickly.

“If I picked up the phone and it was clear after the first handful of words that someone was not calling to report the results, I just hung up,” Sand said.

Mandy McClure, communications director for the Iowa Democratic Party, confirmed that the hotline received “an unusually high volume of inbound phone calls to its caucus hotline, including supporters of President Trump.”

“The unexplained, and at times hostile, calls contributed to the delay in the Iowa Democratic Party’s collection of results, but in no way affected the integrity of information gathered or the accuracy of data sets reported,” McClure said in a statement.

The telephone reporting problems added to other issues, notably a smartphone app that did not work for some people and that also had a coding problem that prevented results from being reported properly, pushing more caucus volunteers to the phone lines.

Iowa Democratic Party officials said that party staff members and volunteers flagged and subsequently blocked repeat callers who appeared to be reaching out in an attempt to interfere with their reporting duties. These included callers who would hang up immediately after being connected and callers who expressed support for Trump and displeasure with the Democratic Party.

It’s unclear how many prank calls the party received or how much they contributed to wait times. Some calls came from Iowans looking to confirm details of their evening’s caucus, party officials said.

The party has not responded to requests for information on how many individuals were manning the phone lines on Monday night.

The Trump campaign denied any affiliation with people clogging phone lines on Monday night.

“We don’t know anything about this, but perhaps Democrats should consider using an app that works," communications director Tim Murtaugh said. "It's laughable that they would try to blame Trump for their own incompetence."

Several officials at caucuses attended by NBC News reporters struggled with lengthy hold times that made it impossible for them to report results.

4chan, which hosts an anonymous and often extremist politics board called /pol/ whose users have largely supported Trump since 2015, is known for extensive online political trolling and targeted harassment campaigns.

On debate nights, 4chan users often direct one another to swarm and manipulate specific online polls on other websites with repeat votes, a practice known as “brigading” in online communities. The polls would then be used by politicians and partisan websites to claim shocking upsets.

Users on 4chan are anonymous, and usernames are randomly generated with each new thread.

Some users on 4chan pushed back against users claiming to spam phone lines on Monday night. One user said he didn’t want other trolls “making us the scapegoat for the DNC.”

“I can’t wait for the news headlines saying nefarious trolls ruined the caucus,” another added.

Two precinct chairs said they were unaware of any interference with the hotline and doubted it made much of an impact.

“I wouldn’t blame the Republicans,” said Tom Courtney, co-chair of the Des Moines County Democratic Party and a precinct chair. “I’d love to blame the Republicans and the Trumpers, but I don’t know.”

Mike Carberry, chair for a precinct in Iowa City, also said he doubted prank calls were the primary reason for long wait times.

“I’m sure that they got some calls, but those could be sorted through relatively quickly,” he said.

Another hotline staffer who asked to remain anonymous said they were aware of the prank calls but that they were not the main reason that results were delayed.

“It was definitely a problem,” the staffer said. “But it was definitely not the reason that results were a mess.”