A look at previous shootings around the world
DECEMBER 1989, CANADA:Marc Lepine (25) stormed Montreal's École Polytechnique, killing 14 women. Four men and eight other women were injured before Lepine turned the gun on himself.
MARCH 1996, BRITAIN:a gunman burst into an elementary school in Dunblane in Scotland and shot dead 16 children and their teacher before killing himself.
MARCH 1997, YEMEN: a man with an assault rifle attacked hundreds of pupils at two schools in Sanaa, killing six children and two other people. He was sentenced to death the next day.
JUNE 2001, JAPAN:Mamoru Takuma, armed with a kitchen knife, entered the Ikeda Elementary School near Osaka and killed eight children. Takuma was executed in September 2004.
FEBRUARY 2002, GERMANY: in Freising, in Bavaria, a former student thrown out of trade school shot three people before killing himself. Another teacher was injured.
APRIL 2002, GERMANY: in Erfurt, eastern Germany, a former student opened fire at a high school in revenge for being expelled. A total of 18 people died, including the assailant.
SEPTEMBER 2004, RUSSIA: at least 326 hostages -- half of them children -- died in a chaotic storming of a school in Beslan after it was seized by rebels demanding Chechen independence.
- Guardian, Reuters
APRIL 1999:two teenagers at Columbine school in Littleton, Colorado, shot dead 12 fellow students and a teacher, and wounded 23 others, before killing themselves. It was the worst campus killing incident until yesterday.
MARCH 1998:two boys aged 13 and 11 opened fire on fellow students in Jonesboro, Arkansas, killing four girls and a teacher. Ten others were wounded. The boys were jailed.
MAY 1998:a 15-year-old shot dead two fellow students in a school cafeteria in Springfield, Oregon, after shooting dead his parents. He is serving 112 years in jail.
MAY 2000:on his last day at school, a 13-year-old shot dead one of his teachers in Lake Worth, Florida, for stopping him talking to two girls.
APRIL 2003:a 14-year-old shot and killed the head teacher in a junior-high cafeteria in Pennsylvania. He then killed himself.
MARCH 2005: a 16-year-old in Minnesota shot and killed five fellow students, a teacher and a security guard on a reservation in what became known as the Red Lake massacre. He had earlier killed two relatives. He shot himself.
SEPTEMBER 2006: an armed man took six girls hostage in Platte Canyon high school in Colorado. He killed one, and then himself.
SEPTEMBER 2006:in Cazenovia, Wisconsin, a boy (15) shot dead the head teacher the day after he had disciplined him for smoking on campus.
OCTOBER 2006:a gunman shot dead five girls at an Amish school in Pennsylvania, before turning his gun on himself.