WASHINGTON — A woman in her 20s was stabbed in the neck Thursday morning as she walked along a trail adjacent to the Vienna Metro Station.

She was expected to survive her injuries, Fairfax County police said.

The stabbing launched an hourslong manhunt for her attacker that involved police dogs, a police helicopter and officers in patrol cars and on foot.

“Right now, we are operating as if it was random,” Fairfax County police Officer Don Gotthardt said. “The suspect is still at large.”

The woman told police she was walking on the Gerry Connolly Cross County Trail near the intersection of Vaden Drive and Sprague Avenue — a neighborhood near the south entrance to the station — when she was attacked just after 7:30 a.m.

The woman told police she was approached from behind by the man, who ran away after stabbing her.

Police were searching for a man who is about 5-feet-4 wearing a white T-shirt and possibly shorts.

Police want to hear from anyone who might have seen anything. Information can be reported by phone, 703-691-2131, or by texting “TIP 187” plus your message to CRIMES (274637).