Rise in bomb threats after Columbine

The Columbine shootings sparked more threats of violence

Schools in the United States received at least 5,000 bomb threats in the six months after the Columbine High School shootings, an education safety group says.

According to the National School Safety Center, many schools reported fivefold increases in threats after the incident at the school in Littleton, Colorado, in which 12 students and a teacher were killed.

It said the threats meant thousands of classroom hours were lost.

Ronald Stephens, the group's executive director, said: "Every time you ratchet up the level of violence, it tends to redefine deviancy.

"We've transitioned from fistfights to gunfights, and Columbine introduced a new dimension called explosive devices."

No single body keeps a record of the total number of bomb threats to US schools - many agencies say real violence leaves little time to keep track of pranks.

Exemptions granted

Some states leave the task to individual schools or police departments.

States where bomb threats are recorded reported significant increases after the Columbine shootings on 20 April, 1999.

California had 548 school bomb threats in the 1998/99 school year - 80% of them after the Columbine killings, according to state Education Department spokeswoman Jean Scott.

She said that in the previous school year, California schools had received only 236 bomb threats.

In Pennsylvania during the 1998/99 school year, 13 of the state's 501 school districts could not provide the 180 days of class required by state law because they lost too many days to bomb threats or other violence.

The Education Department granted all 13 an exemption, but spokesman Al Bowman said students in the state had never lost so much schooling because of threats.