The Washington Post’s editorial page has found “problematic” sourcing in five columns written by Fareed Zakaria and will likely note the lack of attribution in archived editions of the articles, the section’s editor said.

Fred Hiatt, The Post’s editorial page editor, said he would act after the anonymously written blog Our Bad Media on Monday posted, side by side, excerpts from six Zakaria’s columns and work published earlier by other writers. Zakaria used language that was identical, or strikingly similar, to what others had written.

Hiatt, who reviewed Zakaria’s work after the posting, said that five of the six columns posted by the blog “strike me as problematic in their absence of full attribution” to the original writers.

“This is unfair to readers and to the original sources,” Hiatt added. “We will take a fuller look over the next day or two, but we probably will attach messages to the archived editions of the five original columns.”

Since August, Our Bad Media, which is written by pseudonymous bloggers, has posted numerous examples of alleged plagiarism by Zakaria, a widely syndicated columnist, book author and TV host. The examples include Zakaria columns published by Time, Newsweek, Slate and the New Republic and transcripts of “Fareed Zakaria GPS,” the Sunday morning public-affairs program he hosts on CNN. The blog has also accused Zakaria of committing extensive plagiarism in his best-selling book, “The Post-American World,” published by W.W. Norton.

Time and CNN briefly suspended Zakaria in 2012 after he acknowledged that he had plagiarized sections of a New Yorker magazine article about gun control for a Time column. Slate and Newsweek have posted editor’s notes over some of his columns, citing inadequate attribution.

Hiatt noted that the five Post columns in question — which cover such topics as terrorism in Spain, domestic politics and the economy — were published prior to Zakaria’s 2012 suspension. “At that time, he said that he was overextended and that he would simplify his schedule to put more priority on his column and to make sure no such problems recurred,” Hiatt said.

Hiatt defined plagiarism as “the illicit copying of someone else’s words” and drew a distinction between that and inadequate attribution, which is typically considered a lesser journalistic transgression. Hiatt said, for example, that a quote from a Japanese journalist cited by Zakaria in a 2010 column should have been sourced to the Australian newspaper that published the quote, but that it did not meet the “illicit copying” threshold.

Hiatt said that a sixth Zakaria work cited by the blog — a 2009 column about Iraqi Kurds — was on the same theme as a New York Times editorial published three days earlier, but “it does not strike me as either plagiarism or a failure to attribute.”

Zakaria did not respond to a request for comment Monday.

An earlier post by the blog cited two columns Zakaria wrote for The Post, but Hiatt said those columns raised no issues.

The Post’s editorial pages are edited independently from its news columns.