"He was horrified and his immediate reaction was one of deep concern for the families of the victims, the victims themselves, the students, the professors and all the people of Virginia who have dealt with this shocking incident," White House deputy press secretary Dana Perino said. "His thoughts and prayers are with them."

"The president believes that there is a right for people to bear arms, but that all laws must be followed," Perino said, noting that Bush and Education Secretary Margaret Spellings held a conference on school gun violence last October. "Certainly, bringing a gun into a school dormitory and shooting ... is against the law and something someone should be held accountable for," Perino said.

In the House, which returned Monday from a two-week recess, Speaker Nancy Pelosi, D-Calif., interrupted proceedings to lead a moment of silence in remembrance.

"As the Virginia Tech community struggles with the mourning and questioning that is certain to follow, the continued prayers from this Congress are with the students, their families, the faculty and the staff at Virginia Tech," she said on the floor of the House.

A gunman opened fire in a dormitory and classroom at Virginia Tech, situated in the city of Blacksburg in southwest Virginia. The gunman was killed but it was unclear whether he was shot by police or took his own life. After the shootings, all entrances to the campus were closed and classes were canceled through Tuesday.

The university reported shootings at opposite sides of the 2,600-acre campus — first at about 7:15 a.m. at a coed residence hall that houses 895 people and about two hours later at an engineering building. One student was killed in the dorm and the others were killed in a classroom, according to Virginia Tech Police Chief W.R. Flinchum.