Seven people were arrested after protesters blocked the entrance to an atomic weapons site in Berkshire.
Seven people were arrested during Monday's demonstration
The blockade was part of a campaign against plans to build a new laser laboratory at the Aldermaston Atomic Weapons Establishment (AWE).
Project Orion will house a powerful laser which replicates the physical conditions of a nuclear reaction.
On Monday morning, about 45 people blockaded two gates and used lock-on devices to link themselves together.
They believe the new facility will test a new generation of nuclear weapons.
The demonstration was the latest move in their battle to fight the multi-million pound upgrade, which was approved by a West Berkshire Council planning committee last week.
The laser will replicate the physical conditions of a nuclear reaction
Supt Paul Kirkland said: "Our aim today was to facilitate a lawful and peaceful protest, in partnership with the MDP [Ministry of Defence Police] and AWE.
"We also deployed officers to minimise disruption to the rest of the community and prevent traffic problems in the area."
MDP officers arrested seven people for unlawful obstruction of the highway.
Project Orion is part of a three-year, £1bn Ministry of Defence boost for AWE.
AWE has said it wants to change the appearance of the site from that of an old industrial complex to a centre with a reputation for scientific and technical excellence.
The company is also planning to upgrade accommodation and office facilities.