Police have cleared the protest camp against the Mühleberg nuclear power station which was set up in the city of Bern at the beginning of April.
The city government issued a statement saying the decision to clear camp outside the headquarters of BKW Energy, which operates Mühleberg, had been taken after the activists had refused to dismantle the tents despite lengthy discussions.
It said it would have been prepared to allow a permanent vigil, but had made it clear from the beginning that it would not tolerate a camp with a permanent population.
Its aim had been to remove the camp without using force. The police had detained 26 people and checked their documents. The tents and other material had been taken away by the authorities, and can be collected by their owners, the statement said.
It added that it had now withdrawn its permission for a vigil and would not allow the area to be re-occupied.
The Mühleberg Abschalten (Switch off Mühleberg) association accused the Bern city government of taking the side of the nuclear lobby after the cantonal parliament decided last week not to do anything to take Mühleberg out of the grid.
But it said the protest would continue until the power station was switched off.
About 200 people gathered around the site for a lunchtime protest picnic on Tuesday, with flags and placards. The event passed off peacefully.
On Tuesday evening, several hundred demonstrators marched through Bern peacefully to protest the clearing of the camp.
swissinfo.ch and agencies