CHICAGO (WLS) -- Republican presidential candidate Donald Trump sent out a series of tweets Wednesday morning claiming Ted Cruz's victory in the Iowa Caucus was a result of fraud.
In attacks posted on his official Twitter account Wednesday, Trump says "either a new election should take place or Cruz results nullified."
Cruz came under fire in advance of the caucus when his campaign sent out "Voter Violation" mailers that Iowa election officials blasted as misleading.
The literature was labeled "Voter Violation" in bold red letters, with the words "official public record" across the top, ABC News reported. The letter lists the name of the resident -- as well as the specific names of their neighbors -- along with a grade for how often they've voted.
Rubio circulated a similar mailer labeled a "report card," but it did not include language implying a violation.
A previous tweet posted by the billionaire businessman accused the Cruz campaign of telling Iowa voters that Ben Carson was quitting the race so he could steal Carson votes.
Trump came in second behind Cruz in Monday's leadoff Iowa caucuses - which he had previously described on Twitter as a "long-shot great finish."
The Associated Press contributed to this report.