IRVING, Texas (CBSDFW.COM) – Irving Police are trying to figure out who sent a threatening letter to a family telling them to “RETURN BACK TO YOUR COUNTRY.”

Police said right now this is an isolated incident.

“We take harassment and hate crime extremely serious. An investigator has been assigned to this case,” Irving Police said Monday on Twitter.

Return Back To Your Country letter (credit: Irving PD)

Police want to hear from anyone else who may have received the letter.

Anyone with information on where this letter was generated from and who is responsible for it, please contact: Investigator Cunningham –

Irving Police are working with the U.S. Postal Service on the investigation.

Caroline Vandergriff