A wave of racist text messages summoning Black people to report for slavery showed up on phones across the United States, prompting the scrutiny of the F.B.I.
The N.A.A.C.P. said that messages were received in nine states, and attorneys general in at least four other states reported the same.
The F.B.I. said in a statement on Thursday that it was “aware of the offensive and racist text messages” and that it was coordinating with the Justice Department and other federal authorities.
The White House also condemned the racist text messages and said that federal and state officials were investigating them. Federal and state officials were trying to determine the origin of the messages, which continued to send shock waves through the country on Friday.
“Racism has no place in our country, period,” Robyn Patterson, a White House spokeswoman, said in a statement. “We strongly condemn these hateful messages and anyone targeting Americans based on their ethnicity or background.”
The Louisiana attorney general’s office traced the messages to an encrypted virtual private network originating in Poland. But the state’s attorney general, Liz Murrill, said in an interview that the network was “masking” the sender, which could be in the United States or “anywhere in the world.”