WASHINGTON (AP) — Several federal and state agencies are investigating how racist mass texts were sent to Black people across the country in the wake of the presidential election this week.

The text messages invoking slavery were sent to Black men, women and children, prompting inquiries by the FBI and other law enforcement departments.

The anonymously sent messages were reported in several states, including new york, Alabama, California, Ohio, Pennsylvania, Maryland and Tennessee. The FBI said it has communicated with the Justice Department about the messages, and the Federal Communications Commission said it is investigating alongside federal and state law enforcement.

“These messages are unacceptable,” said a statement from FCC Chair Jessica Rosenworcel. She said the agency takes “this type of targeting very seriously.”

While the texts varied somewhat, they all instructed recipients to “board a bus” that would transport them to a “plantation” to work as slaves, officials said. They said the messages were sent to school-aged children and college students, causing significant distress.

Whoever sent the messages used a VPN to obscure their origin, Louisiana Attorney General Liz Murrill said Thursday morning.

The Maryland Attorney General’s Office said it had received multiple reports of racist text messages being sent to Black residents, including children. In a news release Thursday night, officials said the messages appear to be part of a nationwide campaign targeting Black people in the wake of the election.

“These messages are horrific, unacceptable, and will not be tolerated,” Attorney General Anthony Brown said in a statement. Officials asked recipients of the texts to report them to local law enforcement.

Brown said it’s disturbing that children were included in datasets more typically collected on adults, such as campaign donors or magazine subscribers.

“This is an intimidating, threatening use of technology” that likely violated multiple laws,” Brown said. “And our goal is to make sure that we uncover all the facts and then use all the tools and resources available to us to hold accountable whoever is behind these text messages.”

Phone service provider TextNow said that “one or more of our accounts” were used to send the racist text messages and that it quickly disabled those accounts for violating its terms of service.

“As part of our investigation into these messages, we learned they have been sent through multiple carriers across the US and we are working with partners and law enforcement cooperatively to investigate this attack,” it said in a statement Friday.

Major providers AT&T and Verizon both said it was an industry-wide problem and referred comments Friday to an industry trade group.

The US wireless industry blocked thousands of texts and the numbers sending them,” said Nick Ludlum, SVP & Chief Communications Officer of CTIA, a wireless communications trade association. “Through CTIA’s Secure Messaging Initiative, participants have identified platforms bad actors used to send these messages and are working with law enforcement on this matter.”

These racist text messages span the entire country, predominantly targeting Black Americans, and more specifically Black children as young as middle schoolers.

Nicole, a mother in North Carolina who asked not to use her last name because of her profession, said she was disturbed and concerned by the messages her high school daughter showed her Thursday night. The texts instructed her to get ready to go back to the plantation. This was her daughter’s first real experience with this type of racism, Nicole said, and as a parent she didn’t want to have to have these conversations with her kids.

“It’s like a slap in the face and it shows me that it is still an issue that has not changed at all,” she said.

Nicole said her daughter didn’t really say much after the text, deleted the message, and went to bed. As for Nicole, she said she had to sit and process her feelings. She said the situation was so shocking that it didn’t feel real, and she felt sad for her daughter.

“She has a lot of friends of different races. She’s the one that doesn’t see color and she doesn’t see a difference. So, I feel like for her, it really showed her that everyone isn’t like her,” Nicole said. “Racism is still a very prominent thing in our country right now.”

Nicole said that parents have to be vigilant, especially with older children, and have the tough conversations, even if you don’t want to or feel like you have to.

“Whatever way it makes your child feel, approach it with open arms and be very receptive to it and just take it day by day.”