Specialist equipment has started arriving at a shale gas fracking site in North Yorkshire amid protests and arrests.
Third Energy was granted planning permission for the fracking site at Kirby Misperton in May 2016.
About 60 protesters gathered at the entrance. Two men, 33 and 69, were arrested for obstruction.
The company has not received final consent to begin fracking, but expects to start before the end of the year.
Devices to erect noise barriers were among the equipment being transported earlier, before the company starts hydraulic fracturing.
Supt Alisdair Dey, of North Yorkshire Police, said the force would act impartially in dealing with protests at the site.
"We have a duty to make sure that people who want to assemble and protest do so safely, balanced against a duty to ensure that businesses can go about their lawful commercial activity," he said.
The arrested 33-year-old man was later released without charge from custody, said police.
Last week North Yorkshire County Council agreed planning conditions for the work to begin.
Since then protesters have tried to stop maintenance vehicles entering the site during stand-offs with police.
Several were moved away from the site entrance on Monday while a generator was delivered.
Fracking is the process of drilling down into the earth before a high-pressure water mixture is directed at rock to release the gas inside.
Opponents say it can cause water contamination, earthquakes and noise and traffic pollution.
Kirby Misperton, between Malton and Pickering, is due to be the first UK site to carry out the technique since a ban was lifted in 2012, the BBC understands.
Third Energy said it had been operating safely for 20 years in the area and, left alone, it would continue to do so.
John Dewar, director of operations, said "After almost three years of planning it is very rewarding to now be starting work at the well site.
"We look forward to running a safe and successful operation that will be carried out with minimal impact on local residents and the environment."
Protesters have already lost a legal challenge against North Yorkshire County Council's decision to grant planning permission at the site, but have vowed to continue to oppose it.
A number have been camped out close to the site for more than eight months.