Sacred Aboriginal cultural and burial sites will be destroyed by the development of a coalmine in northern NSW, elders say.

Gomeroi elders have called on federal environment minister Greg Hunt to implement a 48-hour halt on works "in a desperate attempt to save burial sites and sacred places" from bulldozers at Whitehaven Coal's Maules Creek mine project near Boggabri.

They say they cannot understand why they have waited more than a fortnight for a response from the minister.

"The minister knows the bulldozers have been destroying our culture and heritage all day, every day, including the weekend," the elders said in a statement.

"Whitehaven [is] ripping the guts out of our sacred sites right now. We fear that by the time minister Hunt finally decides he has finished looking at our application carefully, it will be too late."

Protests against the $767m mine and the damage it will do to a surrounding forest and the Aboriginal sites have been continuing for several weeks.

Several activists have been arrested and charged after locking themselves to gates and bulldozers while trying to stop work at the proposed open-cut coalmine.

After days of increased action, authorities last Tuesday closed the forest, effectively blocking protesters from entering for fear of fire.

Anyone caught entering the forest, which is closed for the rest of the fire season, could be hit with a $2,200 fine.

Comment is being sought from Hunt.