Events marking the first anniversary of the Occupy Wall Street movement include a rally this afternoon in Ottawa where protesters are taking to Confederation Park, as MPs return to the House of Commons following their summer break.

About 100 Occupy Ottawa supporters, who could be heard chanting "Stephen Harper's got to go" as they made their way to Confederation Park, are being joined by members of Occupy Toronto and various unions Monday to speak out against cuts to public services and jobs.

Protesters are also demanding that Prime Minister Harper resign and pushing for systemic change.

Among other things, they're demonstrating against legislation passed before Parliament closed for the summer that contained amendments to dozens of pieces of legislation, including employment insurance and Old Age Security. As well, the government's ongoing downsizing of government departments and agencies is affecting hundreds of public service workers.

'We said a year ago it's a long game.'—Sasha Wiley Shaw, Occupy Vancouver member

Ottawa is one of several Canadian cities participating in worldwide Occupy events to mark the first anniversary of the grassroots movement against economic disparity and social injustice.

In Vancouver on Monday evening, some 50 protesters marched through the city – chanting slogans in support of the environment, free public transit and other causes – to the corporate offices of Enbridge. They scrawled chalk graffiti on the entrance and surrounding sidewalk denouncing among other things the energy company's proposed Northern Gateway pipeline and Prime Minister Stephen Harper.

"We don't want the pipeline and we don't want Harper," one speaker told the crowd before leading an anti-Harper chant.

Monday's rallies started in New York City, with protesters converging on the financial district and attempting to block sidewalks leading to the New York Stock Exchange (NYSE) early in the morning. Police dispersed protesters, and arrested more than 100 people.

Hundreds were participating in the New York rally, a far cry from the thousands who launched the movement in the city's streets and parks last year.Monday was marked by more arrests of Occupy Wall Street activists during the third day of the commemoration of the launch of the movement. (David Common/CBC)

"Police are in force and have barricaded streets around Wall Street," CBC's David Common reported Monday morning from New York City. "If you aren't in a suit, [there's] no chance [of] getting past the barricade."

Common said he had witnessed at least a dozen arrests.

The anniversary commemoration, taking place over three days, began Saturday, when about 300 people marched to a small concrete park in New York's lower Manhattan that served as headquarters for the protest movement and was its birthplace.

Police took at least a dozen people into custody near Trinity Church that borders Zuccotti Park. Police said they made arrests mostly for disorderly conduct, but no total number was released.

Protesters also marched from Washington Square Park and headed down Broadway toward Zuccotti Park, chanting and waving signs.

A shadow of its former self

Common said Monday that protesters just a block from the New York Stock Exchange were "dynamic, on the move, carrying signs and chanting."

Dozens of cities around the world are holding marches and rallies.

Occupy Canada's Facebook page says "Take Canada Back" events are set for 17 cities across the country.

Occupy Vancouver, for one, plans a protest at 5 p.m. local time at the federal building on West George and Hamilton streets, Sasha Wiley Shaw, who was part of an occupation on the north lawn of the Vancouver Art Gallery last year, told CBC News on Monday morning.

The Occupy movement isn't nearly as big as it was more than a year ago, when protesters set up tents in city and community parks around the world near financial centres as their unified front against corporate greed, poverty and inequality.

However, the encampments were broken up by police, and one by one the tent cities were dismantled.

The movement has been criticized for not having leaders or specific demands.

While the community that took shape in Zuccotti Park still exists, and there are communities involved in the movement in other parts of the world, Occupiers mostly keep in touch online through a smattering of websites and social networks.

Shaw, who remains an active Occupy supporter in Vancouver, said she believes the movement continues to grow and spread.

"I was getting Occupy solidarity messages from places like Germany this morning. Thousands of people are back at Zuccotti Park. So, you know, we said a year ago it's a long game. When you look at a one-year-old baby, you don't ask, 'Is that person successful yet?'"

With files from The Associated Press