Updated at 10:30 a.m. Thursday with statements from Donald Trump and Texas Gov. Greg Abbott.

Early voters in Texas have claimed that voting machines in Dallas, Collin, Tarrant and other counties changed their presidential votes from Donald Trump to Hillary Clinton.

The allegations follow a similar pattern: Voters say they voted straight-ticket Republican, but when they reviewed their ballots, they reflected they had voted for Hillary Clinton for president, not Donald Trump.

Their votes for Republicans in down-ballot races were not affected, according to the complaints.

Donald Trump on Thursday expressed outrage on Twitter about the claims of faulty voting machines in Texas.

A lot of call-ins about vote flipping at the voting booths in Texas. People are not happy. BIG lines. What is going on? — Donald J. Trump (@realDonaldTrump) October 27, 2016

But elections officials say the allegations are more than likely false or instances of user error.

Garland City Council member Stephen Stanley said he went to an early voting station at Nicholson Memorial South Branch Library on Tuesday morning while campaigning for candidates on the ballot.

He said around noon a woman came out of the library and told him she had tried to vote straight ticket Republican but the machine said she had voted straight Democrat.

The woman told him a poll worker apologized that the machine wasn't working and instructed her to use another one.

Stanley said he was worried about people who didn't double-check their ballots.

"My question is how many other people didn't know," Stanley said.

Texas Gov. Greg Abbott posted a statement on Facebook on Tuesday urging voters to double-check their ballot before casting their votes. He directed followers to a website where voters can learn how to cast their ballot before going to their polling place.

Dallas County elections administrator Toni Pippins-Poole encouraged all voters to double-check their ballots before submitting them. She said she's received second-hand reports of malfunctioning machines, but no one has logged an official complaint and she doesn't have any names to go with the claims.

"It could be voter error or it could be that the machine needs to be recalibrated," Pippins-Poole said.

She said in each case the voter was eventually able to vote how they wanted to.

Similar situations were reported in Collin County, elections official Bruce Sherbet said, but all the complaints were called in after the voters had left the polling place. By then, polling place workers were unable to determine whether any of their machines were indeed operating in error.

"If we had someone in the polling place tell us, 'Hey, it marked something other than what I marked on the screen,' we would stop the process and ask the voter to show us," Sherbet said. "We can absolutely verify and check that in front of the voter. If there were a problem with a machine, it would immediately be taken out of service."

Frank Phillips, election administrator for Tarrant County, told WFAA-TV (Channel 8) that his office received two complaints Monday, one of which was from a woman who said her presidential vote had switched from Trump to Clinton.

He said the case was resolved. The woman's first ballot was voided and she was moved to another machine. A technician examined the machine she said was faulty but found no problems, according to Channel 8. Election officials could not replicate the error at their headquarters.

"Typically, we've found it's voter error with the equipment," Phillips said. "Sometimes they vote straight party and then click on another candidate. ... There is not an issue with the equipment."

Hector DeLeon, director of communications for voter outreach in Harris County, said his office has not received any legitimate complaints of faulty voting machines.

He said he's aware of the allegations made on social media, but no voters have voiced any complaints to election clerks at polling stations in Harris County. If they had, a presiding judge would have been notified and a complaint would have been filed with the Harris County Clerk's Elections Office.

"At this point, no such process has taken place," DeLeon said.

DeLeon said voters sometimes select a candidate for president twice to reaffirm a vote and deselect their choice by doing so.

Denton County Republican Party chairman Lisa Hendrickson said in a statement that she contacted the Denton County Elections Administration regarding voting concerns.

"They have advised me all machines are now fully functioning," Hendrickson said. "If you wish to early vote you can do so electronically at any polling location in Denton County."

Those wanting a paper trail, she said, must request a paper ballot and can only do so on election day, Nov. 8.

Voters in Amarillo made several claims on Facebook that their votes have been changed from Trump to Clinton.

But Potter County elections administrator Melynn Huntly said her office has not received any reports of faulty voting machines.

Huntley said the touch-screen machines are tested twice before they're approved, and they're calibrated daily to make sure where voters touch is accurately recorded.

If a voter has a complaint about a machine, she said, the machine is closed until a technician can examine it and ensure it is working properly.

"Historically, these complaints are typically voter error," Huntley said.

Shannon Lackey, elections administrator for Randall County, also in the Panhandle, said a report of a faulty machine in her county was most likely an instance of user error.

"A lot of voters only vote every four years," she said. "They're not comfortable with the machines."

She said the woman from Randall County who made a post on Facebook about her experience was simply trying to tell people to double-check their ballots. Lackey said the woman was able to recast her ballot for the candidate of her choice.

"I don't do this because it's fun," Lackey said. "I do it because I believe in what I do. If I didn't believe in the machines, I wouldn't be sitting here doing this."

Election officials recommend that if voters think a voting machine incorrectly recorded votes, they should notify election clerks so official complaints can be filed and incorrect ballots can be voided.

Staff writer Marc Ramirez contributed to this report.