Security concerns at a panel session for a proposed oil pipeline in Canada prompted a suspension of the review process, a Canadian energy regulator said.

According to a report in Canadian news service The Globe and Mail, activists in Montreal descended on a hearing room and charged panel members} from the National Energy Board seated to review TransCanada's proposed multi-billion dollar Energy East oil pipeline.

In a statement, the NEB said it was adjourning the sessions in Montreal because of a "violent disruption" to the proceedings.

"Disruptions like this one compromise the board's ability to conduct the session in a secure manner and also prevent intervenors from having an opportunity to be heard, sharing their views and asking questions," the NEB said. "All participants in this hearing have a right to be heard and with respect."

TransCanada submitted its permit to move for the project more than two years ago. The Energy East project involves the construction of a new pipeline segment and conversion of gas lines for oil service. It's designed to carry 1.1 million barrels of oil per day from Alberta and Saskatchewan to eastern Canadian refineries.

The company says Energy East would give refineries a source of domestic crude in a market otherwise dependent on foreign suppliers. Critics have countered the oil sent from Energy East is meant for exports.

Canadian advocacy group Environmental Defense said the NEB's decision meant it was time to overhaul the federal panel itself, suggesting there may be a conflict of interest between board members and representatives from TransCanada.

"There were serious doubts about the Energy East review from the get-go. Now is the time for the federal government to pull the plug," the group's Patrick DeRochie said in a statement. "Ottawa has to overhaul the NEB and then restart the Energy East process. That's the only credible way to ensure an objective review."

TransCanada's proposed Keystone XL oil pipeline from Alberta through the United States was denied by the U.S. government on environmental grounds. A domestic pipeline from the Bakken shale oil reserve, the Dakota Access Pipeline, is facing stiff opposition from U.S. environmentalists and Native Americans.

Prime Minister Justin Trudeau has expressed reservations about adding pipeline infrastructure in national territory, preferring a greener agenda.

An NEB report found oil production in Canada could increase by more than 50 percent by 2040, though growth will be constrained without the addition of new oil pipeline infrastructure.

There was no TransCanada statement on the Energy East review process.