Canadian singer Neil Young and U.S. actress Daryl Hannah were among thousands of people who took to the streets Saturday in Washington, D.C., urging the Obama administration to reject the proposed Keystone XL pipeline.

The march was the latest protest by the “Cowboy and Indian Alliance,” a group of First Nations people, farmers and ranchers living along the pipeline route. The group has been protesting all week in the U.S. capital, as part of the five-day “Reject and Protect” protest.

Hannah, who led the march on Saturday along with Young, said she decided to lend her voice to the issue in order to draw “attention to those that are suffering because of bad practices.”

“The Keystone, which is just an export pipeline, is really a conduit to the further expansion of tar sands,” she told CTV News Channel Saturday.

Hannah said protesters are “concerned with these extreme forms of extraction that we’re moving towards, as fossil fuel supplies are harder and harder to access.”

Other participants in Saturday’s march included First Nations people from Fort Chipewyan, Alberta.

Eriel Deranger, spokesperson for the Athabasca Chipewyan First Nation, said her community is “on ground zero” of tar sands expansion in the province.

“Our nation has faced the extension of Alberta’s tar sands into our traditional treaty territory…and this expansion is contributing to the annihilation of our land, culture, and the destruction of our waterways,” Deranger told News Channel.

“The keystone XL pipeline is a part of that infrastructure to support the expansion of Alberta’s tar sands, so we join those that are opposed to this pipeline that will spell the expansion of Alberta’s tar sands and the exacerbation of greenhouse gas emissions into the atmosphere,” she added.  

Support for the pipeline has been increasing, a new public-opinion poll suggests. The poll, issued on Wednesday by American polling company Rasmussen Reports, found that 61 per cent of likely U.S. voters were in favour of building the pipeline, while 27 per cent were opposed to the project.

But the pipeline, which would carry crude oil from Alberta to the Texas Gulf coast, has been delayed indefinitely in part due to an ongoing court case in Nebraska, which has been at the centre of the Keystone battle.