The activists began protesting at the Blair House site outside Oakley in Fife yesterday (22 March).
They were trying to stop tree-felling work to clear the site for coal recovery. The area takes in Black Woods area.
UK Coal plans to mine 720,000 tonnes of coal from the site during the next three years.
Police went to the site yesterday to monitor the protest, but there was not believed to have been any damage or nuisance caused.