The National Park Service moved Wednesday to stop sales of the Confederate flag in federal parks, the Loop has learned.

“The National Park Service is asking its cooperating associations, concessions, and partners to voluntarily withdraw sales in their stores of Confederate flags and other items, such as stickers, that depict the Confederate flag as a stand-alone feature,” Park Service spokeswoman Kathy Kupper e-mailed us after we’d inquired early in the day.

The controversy over the display of the flag — sparked by the racist hate killings of nine African-Americans in Charleston, S.C. last week — has prompted that state and others to move to take down such flags at their capitals and to remove monuments honoring odious figures such as a founder of the Ku Klux Klan from government properties.

And giant retailers — such as Wal-Mart, Amazon and Sears — have agreed to stop selling items with the battle flag on them.

But the Park Service’s response to our inquiry Wednesday morning may be the first action taken by a federal agency to stop sales of the flags on federal property. The Park Service says there are “over 70 parks in the National Park System [which includes homes, cemeteries and other sites] which have resources that are related to the history of the Civil War.”

Our inquiry, in turn, was prompted by a Loop Fan’s e-mail noting a Confederate flag for sale at the gift shop at Antietam Battlefield and wondering whether the Park Service “will join the list of those no longer willing to make money off of this symbol of hatred?”

The NPS statement, asking park concessions to “voluntarily” take down the items from their shelves, may reflect concerns that the agency may not have the legal authority to force stores to remove the items.