Black Coloradans report they are among the targets of a national pattern of insulting, racist text messages that sometimes refer to recipients by name and order them to “pick cotton” on a plantation.

The author or authors of the messages were still unknown as of Thursday, according to reporting by the Associated Press, though the messages claimed to have been sent on behalf of U.S. president-elect Donald Trump.

In many cases, the victims have been young adults and children. On Wednesday night, two Fort Collins girls, ages 14 and 16, received messages telling both that they would soon be forced to pick cotton, describing them as “hoodlums” and “negros.”

Their mother, Monique Mance, said she felt disgusted and fearful after reading the messages, which included the 16-year-old’s name and referred to the 14-year-old using a misogynistic slur.

“I feel hurt, because I don’t feel this is what Fort Collins is,” Mance said. “People here are beautiful, and friendly, and nice, and I’ve never had to deal with this. … It was tough to explain this to my daughters. Like, I don’t even want them to walk home from school now.”

She said the incident reminded her of racist abuse endured by Black people of her grandparents’ generation.

“It’s like, really? We’re going back to this?” she said.

Denver Public Schools spokesman Scott Pribble said similar messages were reported to police in at least one Denver high school, and Denver police said they were investigating two incidents where individuals received such messages.

The texts have also spurred inquiries by federal officials, with the Associated Press reporting Thursday that the FBI and U.S. Department of Justice were looking into the matter, as was the Federal Communications Commission. Black residents of New York, Alabama, California, Ohio, Pennsylvania and Tennessee have also been targeted.

Vikki Migoya, a spokeswoman for the FBI’s Denver field office, confirmed the FBI is partnering with other federal agencies in response to tips about the messages.

“The FBI is aware of the offensive and racist text messages sent to individuals around the country, including in Colorado,” she wrote in an email Friday. “As always, we encourage members of the public to report threats of physical violence to local law enforcement authorities.”

The Colorado Attorney General’s Office has also been informed about the messages, though spokesman Lawrence Pacheco said they could not comment on the status of any investigation or complaints.

While it is unclear whether the person or people responsible committed a crime or unlawfully obtained the personal information used to tailor messages for their recipients, the texts have spread fear at a time of heightened political tensions following a presidential election that hinged on issues of immigration and race.

Omar Montgomery, president of the Aurora branch of the NAACP, said he hasn’t heard from anyone in Denver’s sister city who has received the texts. However, he said a thorough investigation by federal law enforcement was crucial in light of the national political climate.

“When we talk about the racial overtones of this election and where the country is at now where people feel emboldened to share things that target specific groups, we’ve got to hit the reset button, regardless of who’s in office, or else these things are going to continue to divide our nation,” he said.

Montgomery also said his branch of the NAACP remains concerned about the mass deportations promised by Trump, nicknamed Operation Aurora by the president-elect’s campaign. He said the NAACP plans to monitor the treatment of Aurora residents who may be subject to deportation.

“Obviously, we’re concerned about people’s civil rights being protected,” he said.

Mance said she hopes there is at least a bipartisan consensus that targeting children with hateful rhetoric is unacceptable.

“I understand we don’t all agree on things, but leave my kids alone,” she said.

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