After Donald Trump's presidential election win, a wave of racist text messages targeting Black people sparked investigations across the United States. The messages, which reference “slave catchers” and “picking cotton,” have been sent to children, college students, and working professionals from anonymous phone numbers.

One widely shared message read: “You have been selected to pick cotton at the nearest plantation. Be ready at 1:00 pm SHARP with your belongings. Our Executive Slaves will come get you in a Brown Van, be prepared to be searched down once you’ve enter the plantation. You are in Plantation Group C. good day.”

Reports of these messages have surfaced in states including New York, Alabama, California, Ohio, Pennsylvania, and Tennessee.

The FBI confirmed it is aware of the situation and is working with the Justice Department and other federal authorities. “The FBI is aware of the offensive and racist text messages sent to individuals around the country and is in contact with the Justice Department and other federal authorities on the matter,” the agency said in a statement. “As always, we encourage members of the public to report threats of physical violence to local law enforcement authorities.”

The origin of the messages remains unclear. Some appear to have been sent using TextNow, an app that allows users to send anonymous messages from randomly generated phone numbers. In a statement to CNN, the company said it believes this was “a widespread, coordinated attack.”

“As soon as we became aware, our Trust & Safety team acted quickly, rapidly disabling the related accounts in less than an hour,” TextNow said.

Trump’s presidential campaign also addressed the issue, denying any involvement. “Donald Trump’s presidential campaign has absolutely nothing to do with these text messages,” spokesperson Karoline Leavitt said in a statement.