(CNN) -- Two people were injured when a parcel bomb exploded on Thursday in the offices of a Swiss umbrella group for the nuclear industry, police said.
The incident occurred in the offices of Swissnuclear in the town of Olten. The pair suffered minor injuries and were taken to a hospital.
Police are investigating and Swissnuclear could not be immediately reached for comment.
Matthieu Buchs, spokesman of the Swiss Federal Office of Energy, confirmed that the approval process for three new nuclear power plants had been stopped because of the disaster in Japan.
Safety standards will be reviewed in all existing nuclear power plants, he said.
Buchs also said Switzerland derives 39.3% of its electricity from nuclear energy. Nuclear energy makes up 10% of the overall production of energy in the country, he said.
Journalist Roman Lehberger contributed to this report.