PARIS, March 23 (AFP) - The vogue among school students for writing blogs has triggered a wave of expulsions in France after angry teachers found themselves the targets of foul-mouthed abuse on the Internet, a Paris newspaper reported Wednesday.

Seven boys have been expelled from three schools across France in the last two weeks, and several others given temporary exlusions, Liberation said.

"School heads are in a delicate position because they have to stop the vogue. They are obliged to make some examples," Benoit Sollard, head of a government committee that monitors the Internet, was quoted as saying.

"But most of the pupils fail to make the distinction between a playground chat and putting cruel comments on public display on the Internet," he said.

The number of student blog sites has exploded in recent months, most of them on a platform offered by the youth-oriented radio station Sky Rock.

"Skyblogs" are growing by 6,000 day and there are now more than 1.5 million, Liberation said.