EDMONTON -- Protesters on both sides of the climate change debate descended on downtown Edmonton as a high-profile activist came to town.

Greta Thunberg was in Edmonton on Friday for the Strike for Climate Action. The march began at Beaver Hills House Park and moved down Jasper Avenue to the Alberta Legislature for the rally.

A number of Indigenous and youth protesters spoke to the thousands of people who attended the rally. Thunberg herself spoke at the rally, thanking Albertans for a warm welcome.

"Thank you for the wonderful reception I've received here in Alberta, people are so nice. I am very proud to be with you here today in Edmonton," she said.

Thunberg reiterated the reason for her climate strikes, which have been taking place on Fridays for several months.

"Young people all around the globe are today sacrificing their education to bring attention the climate and ecological emergency," she said. "We are not doing this because we want to. We aren't doing it because it's fun. We aren't doing it because we have a special interest in the climate or because we want to become politicans when we grow up. We are doing this because our future is at stake."

Thunberg called on political leaders to drop the partisan debate over climate change, asking those in power to "unite behind the science."

Earlier in the day, crowds gathered at Beaver Hills House Park before marching on the legislature. Police estimated the crowd swelled to 4,000 people at the government building, with many saying they were excited to meet the young environmentalist.

"I didn’t know too much about Greta, I just heard her in the news, but when I heard about this event I learned a bit more about her, and I am just absolutely like amazed by not only her passion, but her courage as well," Lily Pallot told CTV News Edmonton.

"We’re already noticing counter protestors show up and unfortunately they’re being a little bit aggressive already so we’ll see how it goes," said Michael James with Extinction Rebellion Edmonton.

The #ClimateStrike rally is ramping up on Jasper Ave. March should start heading to the #ableg in about 15 minutes. People being organized now, waiting for @GretaThunberg to arrive #YEG pic.twitter.com/wurtNgafXG — Jeremy Thompson (@JThompsonCTV) October 18, 2019

The counter-protest was organized by United We Roll for Canada. A convoy to Edmonton began in Red Deer early Friday morning and gathered supporters along the route as they made their way to downtown Edmonton.

"We're just fighting for our rights. Fighting to be heard," convoy participant Albert Sauve said as the group gathered.

"It's a message to anyone that's against oil and gas industry: this is our livelihood. Leave us be," Laura Miller added.

This is the same group that took a convoy of trucks to Parliament Hill in February to protest the carbon tax and show their support for pipelines in Canada.

The City of Edmonton and Edmonton police warned of traffic delays.

Edmonton Police Service did not make any arrests during the protests.

While it would not say how many officers were called in to patrol the event, EPS did note there was "sufficient police presence in the area to guarantee everyone's safety" and that its budget allocates funds for such events.

"Both groups on both sides of this issue were very cooperative with police, shared information when appropriate, and allowed us to coordinate and make sure the (protests were) successful," said Insp. Jonathan Coughlan of the field response branch.

The provincial government wished Thunberg well but has no plans to meet with her. Opposition Leader Rachel Notley and Edmonton Mayor Don Iveson have reached out.