Civil liberties advocates outraged over how police handled protests at the G20 summit assembled at Queen's Park Saturday to demand a public inquiry.

About 1,300 activists called for officials to consider what they describe as "the excessive use of police force" and "the denial of basic rights such as the freedoms of assembly and expression."

Similar events, organized by the same group, were held in other cities across Canada.

Rallies are also planned for Winnipeg and Vancouver over the next week.

About 1,000 people were arrested in Toronto during the G20 summit after protests in the downtown core turned violent.

Nora Loreto of Civil Liberties Now said organizers believe police overreacted to the thousands of protesters who took to Toronto's streets to protest the gathering of leaders of the G20 nations.

"There were a lot of questionable tactics that were undertaken by the police during the G20 summit, and a lot of powers that a lot of people call into question," Loreto told CTV News Channel Saturday in an interview from Toronto.

"So the purpose of today's rally is to put forward a united front and call on all levels of government to implement an independent public inquiry so we can find out who was making the decisions, why they made the decisions that they made, and how come so many people got arrested?"

More than 700 of those arrested during the G20 summit were released without charge within 24 hours, while about 250 are facing various charges.

On June 26, thousands of peaceful protesters followed designated march routes, while others who engaged in so-called "Black Bloc" tactics broke away from the group, damaging buildings and burning police cars.

The next day, police charged a group of demonstrators at a so-called safe zone at the Ontario legislature, and also clashed with protesters during what began as a peaceful demonstration at a temporary detention centre.

Saturday's protests are designed to "voice opposition to the excessive use of police force and an unprecedented curtailment of civil liberties during the G20 Summit in Toronto," organizers said in a news release.

The rallies are endorsed by a wide array of activist organizations, including the Canadian Civil Liberties Association, the Canadian Labour Congress and Greenpeace Canada.

Loreto said organizers expect the rallies to be peaceful, because "the City of Toronto has gone through a lot in the last couple of weeks, and people are in a space where they really need to express themselves and do it in a way that's safe."