INNERKIP, Ont. -- The group spearheading a blockade of an Enbridge pipeline construction site in southwestern Ontario said Wednesday it will continue the protest until its concerns are addressed.

Some 30 activists began their campaign early Tuesday in the community of Innerkip near Woodstock at the site for the pipeline called Line 9.

The blockade dubbed Dam Line 9 is aimed at preventing the installation of a valve near River Thames, which the protesters say isn't adequately protected from the risk of a spill.

Protest spokeswoman Hannah Batten said the activists would remain at the site indefinitely.

The group said earlier Wednesday that talks were planned for that afternoon between Enbridge (TSX:ENB) and the protesters at the request of the company.

But Enbridge denied asking for the discussion.

"No one from Enbridge has requested a meeting," said spokeswoman Kristen Higgins.

"The protesters remain on site. Our priority is to ensure the safety of the protesters and the safety of the site."

Higgins said Enbridge is not able to continue the pipeline work due to the blockade.

Line 9, built in 1976, originally shuttled oil from Sarnia, Ont., to Montreal, but was reversed in the late 90s in response to market conditions to pump imported crude westward.

Enbridge plans to reverse the flow of oil and increase the pipe's capacity, but opponents argue the pipeline puts the environment at risk and that there has been little consultation with aboriginal communities.

The company has said Line 9 has a good safety record.

Earlier this year, Enbridge's plan to flow oil eastward was approved by the National Energy Board, which said its decision would allow the company to "react to market forces and provide benefits to Canadians, while at the same time implementing the project in a safe and environmentally sensitive manner."

The go-ahead was subject to a number of conditions, which included Enbridge being required to undertake activities involving pipeline integrity, emergency response and continued consultation with stakeholders and the public.

Opponents of the Line 9 project often refer to Enbridge's spill in Michigan, where 20,000 barrels of crude leaked into the Kalamazoo River in 2010.