Five cyclists were arrested during European Car Free Day in Dublin on Saturday.
They were later released but may face court appearances at a later date, according to garda∅.
Custom House Quay, outside the Department of the Environment headquarters, was closed from 7 a.m. to 7 p.m, while traffic was not allowed on Merrion Square West between 9 a.m and 5 p.m.
The Critical Mass Campaign, a network of cyclists that campaigns for better cycling facilities in Dublin, took to the streets to do a lap of the city in the afternoon.
They were protesting against the approach Dublin Corporation had adopted to the event this year, which allowed motorists to drive relatively unhindered around the city.
Around 150 cyclists took part in the lap and they were joined by additional supporters when they stopped on O'Connell Street, according to Mr William Campbell, of the Critical Mass Campaign.
Mr Campbell said the cyclists began to play football and volleyball with inflatable balls at the junction of O'Connell Street and Abbey Street at around 3.30 p.m. Garda∅ arrived after around half an hour.
"They started grabbing people. A couple of them were handcuffed," he said.
Mr Campbell described the Garda response as "inappropriate".
"The people involved thought it was ironic that they sent in the forces of law and order to make sure the streets were reserved for cars and not people on Car Free Day," he said. "It was very aggressive compared to the good-humoured nature of the event."
Green Party city councillor Mr Ciaran Cuffe said it was "upsetting" to see cyclists being arrested on Car Free Day.
"I was appalled at the heavy-handed tactics that the garda∅ used in dragging cyclists off the street," he said.
Mr Cuffe added that Dublin Corporation and the Environment Minister, Mr Dempsey, had not done enough to promote Car Free Day.
"There was an insufficient response to an event that's celebrated in 22 European countries, where large areas of cities are closed off to cars," he said. He hoped next year would see a high-profile event."We need a real Car Free Day rather than a token gesture."
Garda∅ said the cyclists arrested at the weekend had breached the Public Order Act. "There was no problem with the protest but some of them sat down in the street and then you're into problems. They were obstructing cars," a Garda spokesman said.
He said garda∅ at the scene had adopted a "low-key approach" and denied the protesters' accusations that heavy-handed tactics were used.
Elsewhere, the event passed off more smoothly. Also participating iwere Galway, Cork, Limerick, Waterford, Saggart, Portlaoise, Clonmel, Greystones and Sligo.
Street entertainments were organised to make the day fun for families.
