Protesters march north on Yonge Street in downtown Toronto on Monday afternoon. (Pras Rajagopalan/CBC)

About 200 protesters walked peacefully, but noisily, through a section of downtown Toronto on Monday afternoon — giving police and the public a taste of what to expect during this weekend's G20 summit.

The demonstration began at Allen Gardens, near Sherbourne Street and Gerrard Street East and worked its way to the centre of the city.

The demonstration was a coalition of several protest groups representing aboriginal issues, housing and health care advocates, animal rights activists and human rights supporters.

The heavy police presence that has been so noticeable in downtown Toronto for the past several days was visible during the protest march.

Scores of police officers kept an eye on the demonstration,keeping it contained and moving. A police van led the march, while dozens of police on bicycles hemmed in the protesters on either side.

One of the people who ran afoul of police was Montreal writer Yves Engler, who is no stranger to political protest. In 2005, he poured a bottle of cranberry juice over Pierre Pettigrew, who was then foreign affairs minister.

On Monday, Engler told CBC News he had been given a lecture by police.

"Basically, the police didn't like the fact that I was standing in a place that they didn't define as an open space for democracy, and they took me to the side and threatened to arrest me and, you know, cautioned me, as they put it," said Engler.

One officer told the protesters that if they took any sort of illegal action, "we will respond to that, OK?"

The one action the group did take was to crowd into a gas station for about 10 minutes. They then left.

Eventually, after marching along Dundas Street and then up Yonge Street, the demonstration ended in front of the Children's Aid Society building on Isabella Street.

It's expected that further, larger protests will erupt across Toronto in advance of the G20 — and on the weekend when the meetings get underway.