Sixteen protesters were arrested as a blockade at a rural site earmarked for exploratory oil drilling by a fracking company was cleared.
The arrests came as anti-fracking campaigners gathered for a second day in the village of Balcombe, West Sussex, where Cuadrilla is poised to start test drilling.
The village has become a focal point for campaigners who have highlighted fears linked to fracking, including the use of chemicals. The controversial method of hydraulic fracturing involves using high-pressure liquid pumped deep underground to split shale rock and release gas.
In Balcombe, some protesters, who include a former page three girl, a "professional clown" and veteran eco-campaigners, have vowed to mount a 24-hour campaign of resistance against fracking.
Sussex Police said on Friday that five people had been held for allegedly causing a danger to road users, and 11 for trying to stop drivers and other workers accessing the site under section 241 of the Trade Union Labour Relations Act.
A police spokesman said some had moved a tree across the entrance to the site, blocking access, but all arrests were made peacefully.
Some activists criticised the police response as "disproportionate". One critic, Ashley Williams, said: "The community are standing up for themselves against a company that is trying to poison them. As soon as regular people put their head above the parapet the state jumps in to defend the interests of a wealthy few."
Police said the arrests were made to "ensure public safety" and came after talks between activists and protest liaison officers failed.
Superintendent Steve Whitton said: "Sussex Police fully supports the right to demonstrate peacefully and within the law and also facilitate the contractors to carry out their business. Our aim is to provide a safe and secure environment for protesters, residents and the contractors, to minimise disruption to the community and to prevent crime and disorder."
Cuadrilla said obstacles blocking the road have now been removed and delivery of equipment has resumed. It hopes to start drilling "as soon as is reasonably possible". It said in a statement: "The police have taken the action they feel is appropriate, which has resulted in some arrests. Cuadrilla has followed all legal and regulatory procedures concerning its exploratory drilling plans and obtained the necessary approvals from the Department of Energy and Climate Change, the Environment Agency, the Health and Safety Executive and West Sussex County Council."