Police were called in to help maintain order as scores of protesters gathered in Toronto Saturday in support of Hong Kong's months-long, citywide uprising calling for democratic reform.

Gloria Fung, president of Canada-Hong Kong Link, says her group joined with Toronto Hong Kongers Alliance to organize a march outside Toronto's Old City Hall.

Fung said they did not expect pro-China protesters to show up as well. She accused them of "intimidation" and "harassment."

Tempers flared and tensions ran high as the two sides tried to drown out each other with shouts of "One China" and "Hong Kong belongs to China" coming from the pro-China group.

Shouts of "no violence" came from the other side.

"We have got the police permit to launch a peaceful march, however, before we could go out to start a march, we noticed that there's a very well-orchestrated counter-rally here by the pro-China camp," Fung told CBC News.

Members of the Toronto Police Service had to separate the two sides more than once.

Tempers flared and tensions ran high as the two sides tried to drown out each other with their chants. (Adam Jacobson/CBC)

The protests in Hong Kong, which have been ongoing since June, were sparked by a proposed extradition law.

"This extradition bill, if enacted, is going to allow China to arbitrarily arrest anybody who is working, travelling, living or even in transit via Hong Kong," Fung, told CBC News at an earlier march in June.