Protesters have launched a blockade at Whitehaven's controversial Maules Creek coal mine project to stop construction at the site.
Anti-mining alliance Lock the Gate said the blockade began on Monday at the site near Boggabri, in northwest NSW, and aimed to turn back "vehicles seeking to clear the forest for construction of rail infrastructure".
"Protesters have established a blockade at the edge of the forest, and are preventing bulldozers from felling trees for an access road," Lock the Gate said in a statement.
"Construction work has been halted and the protesters are vowing to remain in place."
The group claims the project will clear-fell a large area of the Leard State Forest that comprises endangered woodland and wildlife habitat.
"It's opposed by members of the local farming community," Lock the Gate added.
In December, protesters blockading at the mine site were arrested by police.
That action came after the Federal Court dismissed an application by the Northern Inland Council for the Environment (NICE), which had called for the approval granted by former environment minister Tony Burke of the $767 million Maules Creek mine to be overturned.
Whitehaven has previously said the project will create 800-plus jobs and had support from most local residents.
Mine construction is due to begin early this year.