Officials at Virginia Western Community College are investigating a false alarm that put the campus on lockdown Tuesday afternoon, a spokeswoman said.

Outdoor sirens went off at about 2:30 p.m., alerting the campus of the lockdown, said Margaret Boyes. The college also posted information on its Web site and sent text messages to subscribers.

Campus police determined that the lockdown was a false alarm, Boyes said. Classes resumed at 2:42 p.m.

Police are looking into why the sirens sounded. Campus police Chief Craig Harris said the alarm may have gone off because the system was being upgraded.

Nearby Madison Middle School and Fishburn Elementary School were not affected, a Roanoke school spokeswoman said.

-- Amanda Codispoti