IRVING, Texas (NEXSTAR) — The Irving Police Department has assigned an investigator to look into a racist letter threatening violence against minorities.

“American citizens in IT industry and other professional fields have lost their jobs to many Indians and Chinese. We asked that you leave the country without further delay,” reads a copy of the letter posted to social media by Irving police.

The letter goes on to threaten shootings at workplaces and playgrounds if people from minority communities do not leave. Officers say this initially appears to be an isolated incident, but are asking members of the community to come forward if they have received a similar letter.

“We take harassment and hate crime extremely serious,” reads the Facebook post. “An investigator has been assigned to this case.”

Anyone with information is asked to contact the Irving PD.