Kentucky Senate candidates Rand Paul (R) and Jack Conway (D) on Tuesday condemned the stomping of a liberal activist Monday night outside their debate.

Lauren Valle, an activist affiliated with the group MoveOn, was dragged to the ground after attempting to approach Paul as the candidates were arriving at the Lexington, Ky., debate, a video shows. A man wearing a Rand Paul campaign T-shirt could be seen stomping her head twice as Paul was walking into the debate. 

"I was shocked to see video footage of a Rand Paul supporter stomping the head of a woman outside the debate last night," Conway said in a statement. "We can disagree on issues, and I don't know what preceded the incident, but physical violence by a man against a woman must never be tolerated. It is my hope that steps have been taken to ensure this kind of thuggish behavior never happens again in this campaign."

The race between Paul and Conway has been contentious; Conway recently released an ad accusing Paul of belonging to a secret society in college "that called the Holy Bible 'a hoax', that was banned for mocking Christianity and Christ."

Paul's campaign in a statement called the incident "incredibly unfortunate."

"Violence of any kind has no place in our civil discourse and we urge supporters on all sides to be civil to one another as tensions rise heading toward this very important election," campaign manager Jesse Benton said. "We are relieved to hear that the woman in question was not injured."

The incident involving the MoveOn supporter was not the only physical altercation outside the debate. reported that a Conway supporter "stepped on the foot of a female Rand supporter, who recently had foot surgery."

The woman was reportedly wearing a surgical boot, but the incision was reopened as a result of the injury. Police say she refused medical treatment.

Both women reportedly filed assault reports with police.