The campaigners have built a network of tunnels and tree houses at the Mainshill Wood Solidarity Camp near Douglas.
They are opposing Scottish Coal's plans for an open-cast mine on the site.
Advertisement
Hide AdAdvertisement
Hide AdNineteen protesters – 14 men and five women – were arrested on Monday. Police said two more women had been detained yesterday.
A spokesman for the protesters said a crane had to be brought in to remove them from the tower of a fort they had erected.
He claimed that at least 30 others remained dug into the tunnels and tree houses and intended to stay for as long as possible.
Some of the campaigners have been camped at Mainshill for the past seven months.
They are supporting local residents who have objected to Scottish Coal's plan to mine 1.7 million tonnes of coal from the site on Lord Home's Douglas estate.