Update: 22 Dead on Virginia Tech Campus

Virginia Tech says a gunman killed at least 21 students and injured 20 before the shooter was killed.

Police say the gunman was killed after the shootings in a dorm and a classroom at the school in Blacksburg, Virginia.

The school's Web site says the shootings happened at the opposite ends of campus, one at a co-ed residence hall and another at an engineering building.

The university told students to stay inside and away from windows as police swept the campus and worked to establish whether the gunman acted alone.

All entrances to the campus have been closed and classes are canceled through tomorrow.