The tent camp had been set up outside the headquarters of BKW Energy, the company that operates the Mühleberg station, to demand its closure in the wake of the Japanese nuclear crisis in March.
The activists say all 26 campers have been arrested in the pre-dawn operation on Tuesday, while authorities say they have been identified and forced to move, said reports on 20 Minuten and the Corriere del Ticino newspapers.
The Mühleberg Abschalten (“Switch off Mühleberg”) association said more protests remain planned, they said.
The city of Bern said in a statement that the evacuation of the protest camp was prompted by the refusal of the activists to dismantle it, despite several rounds of negotiations. “The council would have been willing to grant a permanent vigil. But it made clear from the start that it will not allow a permanently occupied camp,” it said.
The statement also stressed that the area cannot be re-occupied.