DETROIT (AP) Republican U.S. Senate candidate John James of Michigan said Monday he made a terrible error by inadvertently showing a swastika in his campaigns first TV ad of the general election.

The ad began airing two weeks ago and already was being phased out for a new one, James said, when a left-leaning blog and then the liberal advocacy group Progress Michigan brought attention to the image on Monday. It is briefly shown on a bulletin board in a school hallway while James talks off-screen about failing schools. He said the scene is from stock footage.

I need to fess up and admit this was a terrible error on our part, James, a businessman and military veteran, said during a news conference that was held at his campaign headquarters in the Detroit suburb of Livonia hours after he and Democratic Sen. Debbie Stabenow met for a debate . We should have caught this error and we didnt, and theres no excuse. Im responsible for everything that our team does and fails to do, and I will do everything in my power to make sure this never, ever happens again.