D.C. police have arrested two girls, ages 11 and 13, and charged them with participating in what they described as an egregious and apparently random attack on a woman by as many as nine youths outside Union Station.

The girls were part of a group that included another suspect recording the assault and encouraging the attack to continue.

Two girls, ages 11 and 13, have been arrested in a brutal assault outside D.C.’s Union Station, police say. Video on social media showed a group of kids repeatedly punching and kicking the woman after she walked out of the station,