Female university students in a remote Siberian city have been told not to go out alone after the disappearance of five young women since July.
An atmosphere of fear and distrust has settled on Altai State Technical University, Barnaul, since police and college authorities warned women that a killer could be on the loose.
All the woman who have disappeared - believed abducted and possibly murdered - were aged 16 or 17 and had come to Barnaul to take entrance exams or start their studies as freshers.
The women were last seen on or around the university campus. The first, Yulia Tikhteikova, vanished in July after making her initial application.
Police and university authorities in Barnaul, an industrial city with six higher educational institutions and a student population of more than 22,000, were slow to react as more girls went missing.
It was only after Kseniya Kirgizova failed to come home on August 15 that her father, a local businessman, put pressure on the authorities to publicise the suspected abductions. Her clothes were found earlier this month outside the city on the edge of dense forests that cover much of the surrounding wilderness.
No trace has been found of Liliana Voznyuk, last seen on July 28, or Olga Shmakova and Angela Burdakova, who went missing on August 8.
Ms Kirgizova, who was due to begin her first-year studies on September 1, was taking part in the summer campus clean-up that Russian freshers traditionally perform - sweeping up dust and rubbish and smartening up peeling paint work - when she went missing.
All female students at the university have been warned not to go anywhere unless they are in pairs or a group, even within the confines of college buildings.
The police investigation is not yet officially a murder hunt, and Moscow newspapers, which have seized on the story with lurid and sensationalist theories, are speculating that the girls were abducted to work for drug gangs or for artificial insemination purposes.
The investigation, which has grown to include searches involving up to 100 officers at a time, is focusing on the theory that one man, sophisticated and credible, who knows the university campus well, could be responsible.
"The atmosphere is really horrid; everyone here is very upset by what has happened," a spokeswoman for the university said.