STOCKHOLM — Sweden raised the security alert for the country's three nuclear power plants Thursday after explosives were found on a truck at the southwestern Ringhals atomic power station. Police said they were investigating possible sabotage.

Bomb sniffer dogs detected the explosives during a routine check Wednesday afternoon by security staff while the truck was in the power plant's industrial area near its high security enclosure. Police declined to describe the amount or type of explosive material found.

Bomb technicians said the material lacked a detonating device, meaning there was no danger of an explosion.