Updated

A California TV host and sports radio broadcaster on Thursday accused Democratic Sen. Al Franken of kissing and groping her without her consent in 2006, prompting condemnation and calls for an ethics probe from his colleagues.

Leeann Tweeden posted a blog detailing the alleged incident and also tweeted a picture of what seems to be a grinning Franken standing over her as she sleeps, pretending to grab her breasts.

Franken said he doesn't remember the kissing incident but apologized for posing for the picture. He said he intended it to be funny -- but it wasn't.

“I certainly don’t remember the rehearsal for the skit in the same way, but I send my sincerest apologies to Leeann," Franken said in an initial statement. “As to the photo, it was clearly intended to be funny but wasn’t. I shouldn’t have done it.”

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Tweeden says she was disgusted to learn she was groped as she slept (Reuters)

Franken later issued a detailed statement saying there’s “no excuse” and he feels “ashamed,” while also offering to cooperate in an ethics investigation into the matter.

“I respect women. I don't respect men who don't. And the fact that my own actions have given people a good reason to doubt that makes me feel ashamed,” Franken said. “... I don't know what was in my head when I took that picture, and it doesn't matter. There's no excuse.”

He added, “I am asking that an ethics investigation be undertaken, and I will gladly cooperate.”

SLIDESHOW: FRANKEN'S ACCUSER

Franken’s accuser said in an afternoon press conference that she would accept his apology and stopped short of calling on him to resign from his post. However, Tweeden hinted that there may be more accusers.

Soon thereafter, former Bay Area reporter Melanie Morgan tweeted she had a similar experience with Franken -- she later shared her account online. Morgan claimed Franken kept calling her and "badgering" her after a dispute they had about budget numbers on a TV show. But unlike Tweeden's, Morgan's accusations did not seem to be about sexual misconduct.

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The radio host came forward in a shocking open letter on blog (Reuters)

Tweeden said the abuse she experienced took place during a USO Tour in Afghanistan.

Franken, a former writer for "Saturday Night Live," wrote a sketch for the tour in which his character kisses hers on stage. He was an Air America radio host at the time of the incident. He was elected to the U.S. Senate in 2008.

Tweeden said Franken repeatedly pressured her to practice the kiss backstage and at one point forcibly kissed her.

“I immediately pushed him away with both of my hands against his chest and told him if he ever did that to me again I wouldn’t be so nice about it the next time,” she wrote. “I walked away. All I could think about was getting to a bathroom as fast as possible to rinse the taste of him out of my mouth.”

Tweeden said she felt “disgusted and violated” – and that the abuse didn’t stop there.

A photographer, who was with them on their C-17 cargo plane ride back home, snapped a picture of what looks to be a sleeping Tweeden, still wearing her flak vest and Kevlar helmet, and a grinning Franken appearing to grab her breasts.

“I couldn’t believe it,” she wrote. “He groped me, without my consent, while I was asleep. I felt violated all over again. Embarrassed. Belittled. Humiliated. How dare anyone grab my breasts like this and think it’s funny?”

Tweeden said she thinks Franken asked someone to take the photo “knowing I would see it later, and be ashamed.”

The accusations against Franken come on the heels of an avalanche of allegations out of Capitol Hill on sexual harassment and gender hostility. Multiple incidents out of D.C. and other state houses have shed light on the difficulties victims face when trying to report their accusers.

Senate Majority Leader Mitch McConnell, R-Ky., said the Ethics Committee should review the Franken matter, and Minority Leader Chuck Schumer echoed the call.

“Sexual harassment is never acceptable and must not be tolerated,” Schumer, D-N.Y., said in a statement. “I hope and expect that the Ethics Committee will fully investigate this troubling incident as they should with any credible allegation of sexual harassment.”

About 1,500 former Capitol Hill aides have signed an open letter to House and Senate leaders demanding that Congress put in place mandatory harassment training. They’re also calling to revamp the Office of Compliance, a small office that deals with these complaints and that few knew even existed.

Fox News' Brooke Singman contributed to this report.