SHREVEPORT, La. (AP) - Police in Louisiana and the FBI are investigating a threat against a Shreveport mayoral candidate.

Louisiana State Police trooper Glenn Younger told the Shreveport Times on Thursday an investigation was opened after Caddo Parish Commissioner Steven Jackson claimed he was anonymously threatened. Jackson said in a news conference Wednesday he would be lynched if he did not drop out of the mayoral race.

Jackson, who is black, said an envelope containing a threatening message inside was left at his family home. He showed a copy of paper depicting his face placed on top of a head in a noose with the word "Rope" below.

Under the image, Jackson was called a racial slur and urged to stop his attempt to remove a Confederate monument from the ground of a local courthouse.