STOCKHOLM -- Swedish police arrested four campaigners on Wednesday after they spent 28 hours hiding in the grounds of a nuclear power station in southwestern Sweden. Greenpeace said two other protesters were still hiding at another plant on the eastern coast.
The four were among some 20 people who forced their way into the Ringhals reactor site on Tuesday morning by breaking chains on an outer perimeter gate. Fifty others scaled the outer fences of the Forsmark reactor site, Greenpeace said. Most of the activists were detained soon after illegally entering the enclosures, the environmental group said.
"We still have two guys at the Forsmark site who have not been found," Greenpeace spokeswoman Birgitte Lesanner said. "It just goes to show how bad the security is."
She said the group had staged the action to highlight what it says is poor safety at Swedish nuclear power plants, with some activists cycling into the fenced-off outer perimeter.
"The lack of safety was proven already by the European Union stress tests but they didn't test for people to get in (illegally), which should have been included in the tests," Lesanner said. "People can just go in, like we did on bikes."
The activists did not enter the high security area _ with multiple fences, alarms and gate guards _ where the reactors are situated.
Police in the Ringhals region said they were holding four activists on suspicion of aggravated illegal entry, after releasing most of the 18 protesters they detained on Tuesday.
Ringhals and Forsmark nuclear power officials could not immediately be reached for comment. The Swedish nuclear safety authority did not return calls.
Sweden has 10 nuclear reactors at the country's three power plants: Ringhals, Forsmark and Oskarshamn _ providing about half of the country's electricity.
Its nuclear industry has come under fire for the lack of safety precautions. In June, a small amount of explosives was found on a forklift at the Ringhals plant but officials were unable to say how it got there.
Last year, a fire broke out in a Ringhals reactor after staff had left a vacuum cleaner in the containment building.
In 2010, Greenpeace activists broke into the Forsmark power plant site by climbing a fence and staged a demonstration.