Democratic Sen. Al Franken of Minnesota admitted he "crossed a line" interacting with some female acquaintances during "greetings and embraces for a hug or photo."
"I'm a warm person; I hug people," Franken said, Fox News reports. "I've learned from recent stories that in some of these encounters, I crossed a line for some women -- and I know that any number is too many."
Franklin then apologized for his behavior.
"I feel terribly that I've made some women feel badly and for that I am so sorry, and I want to make sure that never happens again," he added.
Four women have accused of Franken of inappropriately touching them while taking photos, HuffPost reports.
One says Franken harassed her at an event honoring women and called the senator a "a serial groper."
"People are saying that this is a right-wing conspiracy," said one of the women, who chose to remain anonymous. "It’s not. I’m a liberal person ... I voted for him after this happened."
"Men should be held to the same standards regardless of their politics," she added. "He’s an imperfect messenger for a progressive platform. He can’t claim to be 'for women' and also grope them."
Minnesota resident Lindsay Menz and Los Angeles radio and TV host Leeann Tweeden also made similar allegations.
On Nov. 20, Menz accused Franken of touching her buttock while posing for a picture at the Minnesota State Fair in 2010.
Before that, Los Angeles radio and TV host Leeann Tweeden said Franken forcibly kissed her during a 2006 USO Tour.
"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," Tweeden said, reports NBC. "I felt disgusted and violated."
Franken was also photographed pretending to touch the ex-Playboy model's breasts while she slept.
A third woman said Franken cupped her butt with his hand at a 2008 Democratic fundraiser, before suggesting the two go to the bathroom together.
"My immediate reaction was disgust," the woman said. "But my secondary reaction was disappointment. I was excited to be there and to meet him. And so to have that happen really deflated me. It felt like: 'Is this really the person who is going to be in a position of power to represent our community?'"
Franken denies part of her claim.
"I can categorically say that I did not proposition anyone to join me in any bathroom," he said.