An unknown person physically assaulted a teenage pro-life demonstrator outside a Planned Parenthood in Roanoke, Virginia, on Saturday for an unknown reason — and it was all caught on video.

What happened?

According to the Daily Caller News Foundation, 15-year-old Purity Thomas was the victim of the assault. She was demonstrating outside the abortion clinic with the pro-life group Students for Life of America.

A press release given to the Daily Caller News Foundation said that Thomas was speaking and praying with women outside the clinic when an angry women walked up to her and threatened to beat her the "f**k" up. The unidentified assailant then stole Thomas' sign, which said: "All people are made in the image of God."

That's when Thomas' peers pulled out a phone and began recording the incident — a very good decision given what the angry woman did next.

Video of the next 30 seconds shows the woman running back to Thomas and her group with the stolen sign under her arm. Thomas can be heard defending her group's right to demonstrate outside the clinic as the woman told the students that "it's not right" for them to be there.

The woman then walks directly to Thomas and punches her in the face. The force of the punch caused Thomas to fall to the ground. According to a commentator on the pro-life group's Facebook page, Thomas is OK except for a "mild concussion."

What did the student group say in response?

Kristan Hawkins, president of Students for Life of America, said:

It’s horrific that a minor expressing love for pregnant women was targeted for violence. But this is not an isolated incident. Across the country we are witnessing a rise in the number of incidents of vandalism and violence against peaceful pro-life speech. We pray that the assailant from today’s attack is brought to justice swiftly. But we also pray for the protection of those who volunteer their time to speak for the innocent, preborn infants and their mothers.

The assailant has not yet been identified.

Watch the video: