Updated at 1:55 p.m.

Two students were killed last night in a shooting at the University of Central Arkansas, in Conway, Ark., about 20 miles north of Little Rock. Immediately after the shooting was reported, at 9:19 p.m., the university activated its emergency-alert system; locked down its residence halls and student center; posted police officers at every entrance to the campus; and limited access to residents and authorized employees, according to a bulletin posted on its Web site.

University officials also canceled classes today. At a news conference this morning, they identified the two students who died as Ryan Henderson, 18, and Chavares Block, 19. A third victim, who was not a student at the university, was treated for injuries and later released from a local hospital.

The university’s police department and local law-enforcement authorities have identified four suspects, two of whom are in custody. The suspects are not students at the university, and the incident does not appear to have been random, said Lt. Preston Grumbles, lead investigator for the campus police, according to the Arkansas Democrat-Gazette.

The incident occurred outside a dormitory, and police officers are examining video of the area recorded by surveillance cameras, according to the newspaper. —Sara Lipka