Herman Cain's presidential campaign is pushing back against allegations that he engaged in inappropriate behavior with at least two women when he was head of the National Restaurant Association.

According to the allegations, first reported by Politico on Sunday night and citing anonymous sources, at least two women accused Cain of making inappropriate comments and contact during his tenure at the trade lobbying group in the 1990s, and the situation prompted the women, who received undisclosed settlements, to leave the organization.

Citing documents it had obtained, Politico said the women, who were not named, complained that Cain made sexually suggestive questions, comments and gestures.

A Cain spokesman denied that anything inappropriate happened and said that the matter was resolved more than a dozen years ago. He called the story thinly sourced and blamed "Washington establishment critics," saying they were eager to bring down the GOP candidate, who "is shaking up the political landscape.''

According to Politico, Cain said Sunday after a TV appearance that he had "thousands of people working for me" over his years as a businessman and he declined to comment on the allegations "until I see some facts or some concrete evidence."