The anti-capitalist protests that have become something of a fixture in Lower Manhattan over the past week or so have taken on a distinctly ugly turn.

Police have been accused of heavy-handed tactics after making 80 arrests on Saturday when protesters marched uptown from their makeshift camp in a private park in the financial district.

Footage has emerged on YouTube showing stocky police officers coralling a group of young female protesters and then spraying them with mace, despite being surrounded and apparently posing threats of only the verbal kind.

NYPD officers strung orange netting across the streets to trap groups of protesters, a tactic described by some of them as "kettling" – a term more commonly used by critics of a similar tactic deployed by police in London to contain potentially violent demonstrations there.

The media here in New York has been accused of being slow off the mark to cover the demonstrations, which have been going on for more than a week. The Guardian was one of the first mainstream news organisation to give detailed coverage to the protests – here are some links to our earlier coverage.

• This is a gallery of photographs taken by John Stuttle last weekend.
• Karen McVeigh visited the camp in Zuccotti Park on Monday
• Later in the week, Paul Harris recorded video interviews with some of the protesters.

Now, however, the local media has paid more attention – almost certainly because Saturday's protest became disruptive, bringing chaos to the busy Union Square area and forcing the closure of streets.

The New York Times quoted one protester, Kelly Brannon, 27, of Ridgewood, Queens:

They put up orange nets and tried to kettle us and we started running and they started tackling random people and handcuffing them. They were herding us like cattle.

The scenes are showing signs of attracting high-profile criticism. Anne-Marie Slaughter, who was director of policy planning, at the State Department from 2009 to 2011, said on Twitter: "Not the image or reality the US wants, at home or abroad," linking to a picture of a police officer kneeling on a protester pinned to the ground.

Here's an extract from a Reuters report, which said the demonstrators were protesting against "bank bailouts, the mortgage crisis and the US state of Georgia's execution of Troy Davis".

At Manhattan's Union Square, police tried to corral the demonstrators using orange plastic netting. Some of the arrests were filmed and activists posted the videos online.

Police say the arrests were mostly for blocking traffic. Charges include disorderly conduct and resisting arrest. But one demonstrator was charged with assaulting a police officer. Police say the officer involved suffered a shoulder injury.

Protest spokesman Patrick Bruner criticized the police response as "exceedingly violent" and said the protesters sought to remain peaceful

And this is a fuller take from Associated Press.

The marchers carried signs spelling out their goals: "Tax the rich," one placard said. "We Want Money for Healthcare not Corporate Welfare," read another.

The demonstrators were mostly college-age people carrying American flags and signs with anti-corporate slogans. Some beat drums, blew horns and chanted slogans as uniformed officers surrounded and videotaped them.

"Occupy Wall Street," they chanted, "all day, all week."

Organizers fell short of that goal. With metal barricades and swarms of police officers in front of the New York Stock Exchange, the closest protesters could get was Liberty Street, about three blocks away.

The Vancouver-based activist media group Adbusters organized the weeklong event. Word spread via social media, yet the throngs of protesters some participants had hoped for failed to show up.

"I was kind of disappointed with the turnout," said Itamar Lilienthal, 19, a New York University student and marcher.