Barnes & Noble Inc. posted its first decline in holiday sales in three years, hurt by a downturn in the coloring-book category, bringing another sign that the Christmas season wasn’t kind to retailers.

Same-store sales sank 9.1 percent for the nine-week holiday period, the New York-based company said on Thursday. Coloring books and other art supplies -- products that had surged last year in part because adults were embracing them -- were particularly weak. Still, Barnes & Noble expects to bolster its operating profit by keeping a tight lid on expenses.

These results add to a bleak outlook from two department-store chains, Macy’s Inc. and Kohl’s Corp., which both cut their annual profit forecasts on Wednesday. Barnes & Noble also has struggled with internal turmoil: The retailer ousted Chief Executive Officer Ron Boire in August, with founder Len Riggio stepping back into the role.

“Although books outperformed the company as a whole, we were not pleased with our results,” Riggio said in the statement. “Fortunately, post-holiday traffic and sales have improved, and we are optimistic for the remainder of the fiscal year.”

The shares fell as much as 5.7 percent to $10.75 in New York, the biggest intraday decline in more than three weeks.

‘Double-Whammy’

“Bookstores and Barnes & Noble had significantly softer traffic and were lapping some unusual benefits of the coloring-book trend of 2015,” David Schick, an analyst at Consumer Edge Research, said in an e-mail. This was a “double-whammy.”’

Last year, Riggio had also blamed the polarizing election season for weighing on sales.

Taking the holidays into account, the company now expects earnings before interest, taxes, depreciation and amortization to be at the low end of its previous forecast of $200 million to $250 million.

“We believe this most unusual retail season may be behind us,” Riggio said.