(The Hill) Defense Secretary Pete Hegseth is warning civilian and military employees that the Pentagon is “tracking” any comments from them that celebrate or mock the Wednesday assassination of conservative activist Charlie Kirk. 

“We are tracking all these very closely and will address, immediately. Completely unacceptable,” Hegseth wrote Thursday on social media.

Hegseth was responding to a statement from chief Pentagon spokesperson Sean Parnell, who earlier said it is “unacceptable for military personnel and Department of War civilians to celebrate or mock the assassination of a fellow American. The Department of War has zero tolerance for it,” using the Trump administration’s preferred name for the Department of Defense.

They did not mention any specific examples of personnel who had reacted positively to Kirk’s death.

Kirk, the 31-year-old co-founder of Turning Point USA, was fatally shot in the neck at the campus of Utah Valley University on Wednesday. After a search, officials identified the suspected shooter as Tyler Robinson, a 22-year-old Utah man.

Both Republican and Democratic political figures including all living former U.S. presidents have condemned Kirk’s assassination, but a small number of social media users have mocked or celebrated the killing, drawing outrage. 

The heads of military services have also warned those under them that any inappropriate comments on Kirk will be met with retribution. Navy Secretary John Phelan cautioned sailors, Marines and civilians they “will be dealt with swiftly and decisively” should they bring “discredit” on the department.

“I am aware of posts displaying contempt toward a fellow American who was assassinated,” he wrote on the social platform X late Thursday. “I want to be very clear: any uniformed or civilian employee of the Department of the Navy who acts in a manner that brings discredit upon the Department, the [U.S. Navy] or the [Marine Corps] will be dealt with swiftly and decisively.”

The official X account for the U.S. Coast Guard, meanwhile, also said it “is aware of inappropriate personal social media activity made by a member regarding recent political violence,” though did not provide specifics.  

“That social media activity is contrary to our core values. With the support of DHS, we are actively investigating this activity and will take appropriate action to hold the individual accountable,” according to the post. “We recognize the harm such behavior can cause and remain steadfast in ensuring that the conduct of our personnel reflects the trust and responsibility placed in us by the American people.”