A 14-year-old girl was sexually assaulted by a stranger outside a library in Woodbridge on Friday evening, authorities said.

The incident occurred about 5:20 p.m. outside the Potomac Library on Opitz Boulevard, authorities said. According to a Prince William County Police Department news release, the girl told investigators she was standing outside the facility, which was closed at the time, when the man approached her from behind. Police said the man sexually assaulted the teen, then left when she received a phone call.

Police described the girl’s assailant as a white man between 18 and 22 years old. They said he was between 6’2” and 6’5”, had a messy beard, thin mouth and pointy nose, and he spoke with a northern accent — possibly as if he was from New Jersey. He was last seen wearing a gray or white jacket with a turtleneck underneath, baggy jeans, white shoes, a gray knit hat and small rectangular glasses.

Anyone with information is asked to call Crime Solvers at 703-670-3700.

Matt Zapotosky covers the Justice Department for the Washington Post's National Security team.