Timeline: US school shootings

October 2007: A teenage gunman reportedly shoots and wounds five people at a high school in Cleveland, Ohio, before killing himself.

April 2007: At least 32 people are killed in two shooting incidents in the campus of Virginia Tech university in Virginia.

October 2006: A 32-year-old gunman shoots dead at least five girls at an Amish school in Pennsylvania, before killing himself

September 2006: Gunman in Colorado shoots and fatally wounds a teenage schoolgirl, then kills himself; two days later a teenager kills the headteacher of a school in Cazenovia, Wisconsin

November 2005: Student in Tennessee shoots dead an assistant principal and wounds two other administrators

March 2005: Minnesota schoolboy kills nine, then shoots himself

May 2004: Four people injured in shooting at a school in Maryland

April 2003: Teenager shoots dead head-teacher at a Pennsylvania school, then kills himself

March 2001: Pupil opens fire at a school in California, killing two students

February 2000: Six-year-old girl shot dead by classmate in Michigan

November 1999: Thirteen-year-old girl shot dead by a classmate in New Mexico

May 1999: Student injures six pupils in shoot-out in Georgia

April 1999: Two teenagers shoot dead 12 students and a teacher before killing themselves at Columbine School in Colorado

June 1998: Two adults hurt in shooting by teenage student at high school in Virginia

May 1998: Fifteen-year-old boy shoots himself in the head after taking a girl hostage

May 1998: Fifteen-year-old shoots dead two students in school cafeteria in Oregon

April 1998: Fourteen-year-old shoots dead a teacher and wounds two students in Pennsylvania

March 1998: Two boys, 11 and 13, kill four girls and a teacher in Arkansas

December 1997: Fourteen-year-old boy kills three students in Kentucky

October 1997: Sixteen-year-old boy stabs mother, then shoots dead two students at school in Mississippi, injuring several others