A burned animal carcass was reportedly left on the doorstep of a Department of Homeland Security staffer as tensions grow between the Trump administration and those who are protesting its "zero tolerance" immigration policy.

The acting deputy secretary of Homeland Security warned employees in a memo released Saturday that "there may be a heightened threat" against agency staffers, CBS News reported. The official said the alert came as "specific and credible threats have been levied against certain DHS employees."

The memo, which said "thousands of employees" have had their personal information released to the public online, reportedly detailed safety precautions staffers could take amid the ongoing backlash of the treatment of illegal immigrants and their families at the U.S.-Mexico border.

"Always keep doors and windows locked" and "be aware of unexpected changes in and around your home," were recommendations made to agency employees. They were also encouraged to call 911 or the Federal Protective Service if they're feeling threatened.

SARAH SANDERS DECRIES 'CALLS FOR HARASSMENT' CITING MAXINE WATERS, RESTAURANT EPISODE

DHS staffers — particularly Immigration and Customs Enforcement agents — in recent weeks have been the target of roughly two dozens threats, according to ABC News. The threats were reportedly sent online.

A senior DHS official, living in the Washington, D.C. area, was reportedly the target of a physical threat. The news outlet reported he found the carcass of a burned and decapitated animal on his front porch.

The increasing number of threats, not only to DHS employees, come as Rep. Maxine Waters, D-Calif., called on her supporters Saturday to "absolutely harass" White House officials in public in an effort to fight back against the Trump administration.

President Trump on Monday in response called Waters "an extraordinarily low IQ person," adding: "Be careful what you wish for Max!"

White House press secretary Sarah Sanders, who was asked to leave a Virginia restaurant over the weekend, said Monday that recent "calls for harassment and push[es] for any Trump supporter to avoid the public is unacceptable."

"We are allowed to disagree, but we should be able to do so freely and without fear of harm," Sanders said. "And this goes for all people, regardless of politics."