KANSAS CITY, Mo. (AP) -The Kansas City Chiefs have barred running back Larry Johnson from team activities pending an investigation into his use of a homosexual slur this week.

Johnson, a two-time Pro Bowl running back for the Chiefs, apologized Tuesday to his team, fans and the NFL ``for the words I used.''

``I regret my actions. The words were used by me in frustration, and they were not appropriate,'' he said. ``I did not intend to offend anyone, but that is no excuse for what I said.''

Johnson posted the slur on his Twitter account Sunday in a response to another tweet. On Monday, he said it again in refusing to talk with reporters, according to a recording made by the Kansas City Star.

The Chiefs and the NFL are investigating.