The Vietnam Memorial Wall in Washington was vandalized on Wednesday, officials said. 

“A red, waxy material was found on one name on the Vietnam Veterans Memorial,” the Vietnam Veterans Memorial Fund tweeted on Thursday. 

The Vietnam Veterans Memorial Fund also tweeted, ”This may have been a result of a visitor attempting to make a name rubbing on their own. Name rubbings should only be done with pencil.” 

“Volunteers are happy to help visitors with their name rubbings. You can also request a name rubbing from us here→http://bit.ly/2aBHhpX” 

The National Park Service has since removed the substance, said the Vietnam Veterans Memorial Fund. 

Fox 5 reported that the incident doesn’t seem to be connected with recent National Mall vandalism.