SARNIA, Ont. -- About 50 environmental and First Nations activists gathered to protest in Sarnia, Ont., as a two-day national conference on oil sands bitumen opened Tuesday.

Carrying signs reading "People Not Profits" and "Solidarity Against The Tar Sands," they gathered to demonstrate their opposition to Alberta oil sands development and proposed pipelines.

They held a rally and water ceremony before community members from Aamjiwnaang First Nation, located in the Sarnia area, led a march to the site of the conference.

The "Bitumen Adding Value Conference" is meant to bring together industry leaders, experts and decision-makers to discuss the production of value-added products from the oil sands resource.

Organizers of the rally say the First Nation is surrounded by a cluster of 60 industrial facilities in Sarnia's "chemical valley" -- including petro-chemical plants and refineries.

Spokeswoman Corrine Tooshkenig told the rally they are concerned about the impact of the developments and pipelines.

"Whether you're yellow, red, black or white, these young people are sending a message to our governments," she said.