Nearly half of the nation's high school students say they have been bullied in the last year and an equal number say they they taunted or teased a classmate, according to a new survey.

The survey of more than 43,000 high school students by the Josephson Institute of Ethics in Westchester comes on the heels of recent suicides by teens relentlessly tormented by bullies.

The institute found that 47 percent of respondents said they had been harassed in a way that was seriously upsetting, and half admitted to bullying a classmate. Nearly a quarter of students said they do not feel safe at school.

"This is a real problem," said Michael Josephson, founder and president of the nonprofit institute, which runs school-based character-building programs. "The numbers are pretty disturbing."

The survey is considered an accurate bellwether of beliefs among young people. The respondents included teens from different age groups, geographic regions, academic levels and socioeconomic groups. The margin of error is less than 1 percentage point.

Conducted since 1992, the survey included questions about bullying for the first time this year. Though kids have always bullied, Josephson said it appears the growing popularity of online social networking and the Internet in general has given bullies a powerful new tool to cause harm.

"At least before you could change your school, or your environment," he said. "That doesn't work