BISMARCK, N.D. — U.S. Sen. Heidi Heitkamp says allegations of sexual harassment against Sen. Al Franken are concerning and that his apology “does not excuse the behavior.”

The North Dakota Democrat says she supports an ethics investigation into her Minnesota colleague.

Leeann Tweeden, a Los Angeles radio news anchor, said Thursday that Franken forcibly kissed her during a skit rehearsal while both were on a 2006 USO tour. Tweeden also posted a picture in which Franken is shown grinning into a camera with his hands on a sleeping Tweeden’s breasts.

Franken has apologized and says he’ll cooperate with an ethics investigation.

Heitkamp says society has been “far too tolerant and dismissive” of sexual harassment allegations, and that cases that are now coming to light are “a sea change that is very important.”