Eight teenage girls have been charged with criminal harassment over bullying at a high school in Ontario, the latest in a string of high-profile and tragic incidents in Canada.

Police in the city of London, 200km west of Toronto, said the girls were arrested after an investigation into physical, emotional and online bullying of another girl at the school.

They were charged and released on a promise to appear in court. They have also been suspended from school.

"Bullying will not be tolerated in our community. The behaviour exhibited by these students is reprehensible and will be appropriately dealt with by the criminal justice system," London Police Service said in a statement.

Police said they made sure the victim was supported and safe before they dealt with the accused bullies.

The arrests follow news last week of the suicide of Canadian teen Amanda Todd, who killed herself after years of bullying, including sexual exploitation on the internet. Todd posted a YouTube video about a month before her death to share her unhappiness and torment.

It was the latest in a string of suicides by bullying victims in Canada which have garnered widespread media attention and sparked a backlash against bullying.

On Monday, a member of parliament called for the creation of a House of Commons committee to come up with a national bullying prevention strategy, and schools, police forces and provinces have launched projects or pledges to stop bullying.

In the London incident, the bullying was reported both directly to teachers and on the school's anonymous website portal, and immediately acted upon, said Bill Tucker, director of education at the Thames Valley District School Board.

Mr Tucker said he believes the bullying had been going on "for some time" before it was reported.

The high school held an assembly on Friday morning to address bullying and show students how seriously incidents were being taken, Mr Tucker said.

He had also been in contact with parents of two of the arrested students, and been encouraged by their reactions.

"They have been supportive of the process and the results and are committed to having their daughters learn from this," he said.

Reuters