GENEVA — A letter bomb exploded Thursday at an office of the Swiss nuclear power industry in the northern city of Olten, wounding two people, police said.
The incident happened hours before another package exploded at a military barracks in Italy, wounding one person, and authorities in Greece defused a mail bomb sent to a maximum security prison where alleged members of an armed anarchist group are on trial.
Authorities haven't drawn a link between the incidents, but Italian news reports citing unidentified sources said Italian investigators believed they were connected. The Italian bombing was claimed by anarchists.
In December, Italian anarchists sent letter bombs to the embassies of Greece, Chile and Switzerland in Rome as part of a campaign with jailed comrades in Greece.
The explosion in Switzerland occurred shortly after 8 a.m. (0600GMT) as staff were opening the morning's post in the fourth-floor office of Swissnuclear, a lobby group representing several Swiss power companies.
Solothurn cantonal (state) police spokeswoman Thalia Schweizer said two female staff members had been taken to a hospital with superficial injuries.
The motive for the attack is still unclear.
"We can't speculate, but we are investigating," Schweizer said, adding that no claim of responsibility has been received.
Opponents of nuclear power in Switzerland have become more vocal in recent weeks as images of the stricken Fukushima reactor in Japan appear on the evening news bulletins daily. Earlier this month the Swiss government froze plans for the construction of new nuclear plants pending a safety review prompted by the radiation leak in Japan. Switzerland has five nuclear reactors currently in operation supplying some 40 percent of the country's electricity.
In Italy, a package bomb exploded shortly after 4 p.m. at the barracks of a parachute brigade in Livorno. A senior military official, Lt. Col. Alessandro Albamonte, was injured on his hands and face after opening the package, though his life was not in danger, the army said.
A carabinieri official in Livorno, who declined to give his name because he wasn't authorized to speak to the media, said an anarchist group had claimed responsibility. The ANSA news agency identified the group as the violent Informal Anarchist Federation, or FAI, which claimed responsibility for the December embassy bombs.
Hours earlier Greek police defused a mail bomb sent to the governor of Korydallos prison in western Athens, where alleged members of an armed anarchist group are on trial.
The padded envelope had Italian postage stamps but no postmark, authorities said. It listed the sender's address as that of the four-nation military alliance, Eurofor, based in Florence, Italy.
Police officials said the device, hidden inside a CD case and rigged using a 9-volt battery, was identical to letter bombs used by Italy's FAI.
Nine suspected members of the armed Greek anarchist group Revolutionary Nuclei of Fire are currently on trial at a court set up inside Korydallos prison, for their alleged role in bombings and other attacks. The group has claimed responsibility for a spate of parcel bombings last November, that targeted embassies and even reached the office of German Chancellor Angela Merkel.