Several authors said they were boycotting the Children’s Literature Festival at a Dr. Seuss museum over a mural that, they say, promotes racial stereotypes.

The authors — including Mo Willems, the Caldecott-winning writer and illustrator behind the popular Pigeon and Knuffle Bunny books — tweeted a joint letter Thursday with the caption: “I wont be attending the Oct. 14 Springfield, Mass., Seuss Museum event as planned. Here is why.”

According to Willems, Lisa Yee (Super Hero Girls) and Mike Curato (Little Elliott), the mural, which illustrates a scene from Theodor Seuss Geisel’s And to Think That I Saw It on Mulberry Street, includes a “jarring racial stereotype of a Chinese man, who is depicted with chopsticks, a pointed hat, and slanted slit eyes.”

“We find this caricature of ‘the Chinaman’ deeply hurtful, and have concerns about children’s exposure to it,” the authors wrote in their joint letter.

The authors had been invited to appear at the inaugural Children’s Literature Festival on Oct. 14 at the Amazing World of Dr. Seuss Museum in Springfield.It was initially described by the museum as “a day filled with books, costumed characters and famous authors.”

Willems, Yee and Curato said they had recently learned about the mural and decided to skip the festival.

“While this image may have been considered amusing to some when it was published 80 years ago, it is obviously offensive in 2017 (the year the mural was painted),” they wrote. “For some children who visit the museum, their only interaction with Asian representation might be that painting. For others, seeing themselves represented in such a stereotypical way may feed into internalized, even subconscious shame and humiliation.

It is incumbent on our public institutions to present all races in a fair manner.

“Displaying imagery this offensive damages not only Asian American children, but also non-Asian kids who absorb this caricature and could associate it with all Asians or their Asian neighbors and classmates.”

The festival has since been canceled.

Theodor Geisel, who graduated from Dartmouth in 1925, was the author and illustrator of the Dr. Seuss series. The college’s medical school was named in his and his wife Audrey’s honor in 1997.

The dust-up comes amid a broader debate about how Dr. Seuss books — some of which depict old stereotypes — fit into an evolving culture.

That debate roared back into the spotlight after Melania Trump sent 10 Dr. Seuss books to a school in each state — and a librarian in Cambridge, Mass., sent them back.

“Dr. Seuss’s illustrations are steeped in racist propaganda, caricatures, and harmful stereotypes,” librarian Liz Phipps Soeiro wrote in a letter last month.

As The Washington Post’s Rachel Chason reported, the librarian argued that rather than sending books to an elementary school in Cambridge, the first lady should have devoted resources to schools in “underfunded and underprivileged communities” that are “marginalized and maligned by policies put in place by Secretary of Education Betsy DeVos.”

In response, White House spokeswoman Stephanie Grisham said giving the books was part of the first lady’s effort to use her platform “to help as many children as she can.”

In their letter Thursday about the festival, Willems, Yee and Curato wrote:

“The career of Ted Geisel, writing as Dr. Seuss, is a story of growth, from accepting the baser racial stereotypes of the times in his early career, to challenging those divisive impulses with work that delighted his readers and changed the times. It was our hope that the administration of the new Seuss-ian institution would be able to take inspiration from Mr. Geisel’s journey and find creative ways to allow children of all backgrounds to feel welcomed (or, at the very least, provide context for this hurtful painting).”

The trio said they expressed their concerns to the museum and were told that “it was the responsibility of visitors to contextualize the oversized painting of the ‘Chinaman’ for their younger wards, not theirs.’”

In a letter sent to the authors, Kay Simpson, president of the Springfield Museums and Dr. Seuss National Memorial Sculpture Garden, wrote that the museum “contains unedited material by Dr. Seuss during his lifetime” and that “we do not alter or edit an artist’s work.”

“Dr. Seuss’s books taught life lessons, from being a faithful friend, to not discriminating based upon appearances, to keeping your promises,” Simpson wrote. “Dr. Seuss was a product of his era and his attitudes evolved over time.

“It is our hope that parents and teachers can use the evolution of Dr. Seuss, including the mural of Mulberry Street in Springfield from Dr. Seuss’s first book published in 1937, as a teachable moment for children in their charge.”