Two protesters have been arrested as preparatory work got under way at a controversial fracking site in North Yorkshire.
A large number of police were on duty near the village of Kirby Misperton as demonstrators massed at outside the compound where the firm Third Energy plans to start fracking for shale gas later this year.
Officers moved protesters from the entrance to the site before lorries began to arrive on Tuesday morning after the firm confirmed it was beginning preparatory work at the KM8 well, which is already drilled.
But the firm again said it cannot begin fracking until it has further consent from the regulatory authorities and the Government.
Protesters estimated around 120 people had gathered to demonstrate in the country lane leading past the compound, and they were met by upwards of 50 police officers.
North Yorkshire Police confirmed two arrests as they cleared demonstrators ahead of the arrival of a number of vehicles at the site.
Ian Conlan, from Frack Free Ryedale, said at the scene: "We have definitely slowed them down. It took them a large amount of time to clear us.
"Some people were dragged away, some were carried away and some walked away. I've been reminding the officers to treat us like human beings especially as many of us are local people.
"This is an absolute farce. They've basically kettled about 80 of us now."
A North Yorkshire Police spokesman said: "Police attended Kirby Misperton just after 10am this morning after a group of protesters caused an obstruction at the hydraulic fracturing site.
"Several protesters were moved away from the front of the site. Two men, aged 33 and 69, have been arrested in connection with the incident."
Superintendent Alisdair Dey said: "We know that there are very different views about hydraulic fracturing, but as the local police, our responsibility is to carry out our duties impartially.
"Police liaison officers have been engaging with the protest community, and will continue to do so, explaining what is acceptable in terms of safety and reasonableness."
John Dewar, Director of Operations for Third Energy, 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."
In a statement, Third Energy confirmed it had begun transporting equipment to the site and would be starting "the pre-stimulation workover phase of the KM8 hydraulic fracturing operations, including preparing the water pipeline".
It said: "Before the hydraulic fracture procedures can begin, Third Energy's hydraulic fracture plan must be approved by both the Oil & Gas Authority and the Environment Agency. Once this is approved, final consent is required from the Secretary of State."
Third Energy secured permission from North Yorkshire County Council last year to use its existing KM8 gas well, sunk in 2013, to run test fracks almost two miles underground.