Bush 'troubled' by school shooting

Bush ordered cabinet officials to find ways for the government to help in the aftermath of recent school shootings, said Dana Perino, a White House spokeswoman.

Bush is "deeply saddened and troubled by the recent school violence," Perino told reporters on a presidential trip to Reno, Nevada.

"It breaks America's collective heart when innocent children who are at school to learn are violently taken hostage and gunned down," Perino said.

Attorney General Alberto Gonzales and US Education Secretary Margaret Spellings will convene a conference next week with education and law enforcement groups to discuss school violence, she said.

Gonzales and Spellings met Monday with Bush's domestic policy adviser, Zinsmeister, to discuss the issue, Perino said.

A truck driver burst into an Amish schoolhouse in rural Pennsylvania Monday and killed at least three girls "execution style" after lining them up in a classroom, police said.

It was the third fatal killing in a US school in the past week.

Last week a 16-year-old schoolgirl was killed when a gunman took six hostages at a Colorado school before opening fire and turning the gun on himself as police stormed a classroom.

On Friday, the principal of a Wisconsin high school was killed after being shot by a student.