Work has halted at the New Millennium and Labrador Iron Mines sites near the Labrador-Quebec border.
About 50 Innu from the Schefferville area have been blocking roads to the mine since Friday.
The Innu say the mining companies are threatening their traditional hunting grounds.
They also say there are no benefits agreements in place with New Millennium Iron Corp. and Labrador Iron Mines Holdings Limited.
New Millennium, which is 27 per cent owned by India's Tata Steel Ltd., says it's respecting the peaceful blockade.
"We have impact benefit agreements (IBAs) with all the First Nations Communities, including the local Innu communities, the Innu of Labrador and the Naskapi," Dean Journeaux, president and CEO of New Millennium, said in a press release.
"The economic impact will be felt by all involved including the First Nations people and contractors working on the various projects. We look to an early resolution by the authorities."
Meanwhile, Labrador Iron Mines says its operations have been "minimally impacted" by the dispute.
"At present, the nature of the barricade is not completely understood by the company, as no direct contact has been made from any of the protesters," Labrador Iron Mines said in a press release.
"Initial reports and protest signs indicate some dissatisfaction with the Quebec government’s Plan Nord initiatives."
The company says it is "committed to open and honest dialogue" on the matter.