The U.S. Army is investigating a National Guard unit in Alabama after a photo of a service member wearing a helmet with a Nazi SS symbol was posted on its social media account, according to reports.

The 20th Special Forces Group, which is based in Birmingham, Ala., posted the photo on its Instagram account Sunday with the caption: "That weekend feeling. Enjoy the rest of your weekend. Don't stop training. Don't get complacent," the Military Times reported.

The posting was deleted after an onslaught of criticism.

The patch on the helmet displayed an SS Totenkopf - also referred to as a "Death's Head" - that shows a palm tree similar to the symbol of Nazi Germany's AfrikaKorps, Task and Purpose reported.

"The use of symbols and patches depicting historic images of hate is not tolerated and a clear violation of our values," said Maj. Russell Gordon, spokesperson for 1st Special Forces Command. "We are aware of the situation and are currently investigating the matter."

He said the logo was banned in 2022 following an informal investigation.

"The patch is an unofficial patch not approved by the command in any kind of way from Third Special Forces Group," Gordon said, Task and Purpose reported. "People started looking at the symbols and researching the symbols and [were] able to clearly identify the history of it. Then the command banned it back in approximately 2022."

The Alabama National Guard is assisting the Command with the investigation, said Mack Muzio, a National Guard spokesperson, the Military Times reported.

The Anti-Defamation League lists the Totenkopf on its website as a hate symbol, noting it was used by the SS groups that guarded the concentration camps.

 "Following the war, neo-Nazis and other white supremacists resurrected the Totenkopf as a hate symbol because of its importance to the SS and it has been a common hate symbol since. It is this particular image of a skull and crossbones that is considered a hate symbol, not any image of a skull and crossbones," the group said.