A protest group official said Sunday that police in riot gear used rubber and pepper bullets against protesters outside a Burlington, Vt., hotel that is the site of the conference.
Avery Pittman of Burlington, spokeswoman for participating protest groups, says police took action against protesters blocking busses that were trying to leave the hotel.
Pittman says protesters were standing in front of the slow-moving busses thought to be carrying conference participants when police used the rubber and pepper bullets.
There was no immediate word on injuries or arrests.
Burlington police didn't immediately return a call for comment.
Raw video posted on the website of the Burlington Free Press appears to show an officer shooting a protester twice at close range.
Earlier Sunday, an estimated 500 to 600 people attended a rally at City Hall before marching through downtown to protest government policies toward the environment, immigrants and refugees, and the economy, protest organizers said.
Protesters were also creating a "human oil spill" at Battery Park to decry the possibility that oilsands crude from western Canada might be shipped across Vermont, New Hampshire and Maine.
Members of the Occupy movement were also holding a regional gathering at the park in the afternoon and evening.
Regional leaders attending the governors and premiers conference had been expected to begin arriving in Burlington on Sunday for meetings Monday.
The protest events, dubbed "Convergence on the Conference," also included a community dinner and presentations from different groups on Sunday, with more events scheduled Monday.
While protesters speak out on a variety of issues ranging from power transmission lines and oil pipelines to Vermont Yankee nuclear power plant, the governors and premiers and their staffs will be meeting "behind closed doors" to discuss issues that have wide-ranging impacts, Pittman said.
"It's clear the governors and premiers are meeting to talk about trade policy, energy and infrastructure," Pittman said. "They're definitely prioritizing profits and money-making over the needs of the people or the impact these proposals will have on us, the people who live on the land and are affected by the decisions."
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