Syracuse University locked down its campus for about an hour Monday after a man was wounded in a drive-by shooting several blocks from campus, police said.

Students were alerted by e-mail of the lockdown after a 20-year-old man sitting in a parked car was shot in the neck from someone in a passing car, police said. The victim, who is not a student, was in critical condition.

The e-mail alert sent at about 11:30 a.m. Monday told the more than 19,000 students to seek shelter and barricade their doors. The lockdown was lifted about an hour later, when police reported the suspect was gone.

Police were pursuing the gunman, who they said apparently targeted the victim.

Syracuse put the alert system in place about a year ago after the Virginia Tech shootings in 2007. The system has been tested before, but this was the first time it was used in earnest.