Firefighters walk out of the Swiss embassy downtown in Rome, December 23, 2010. A package exploded at the Swiss embassy in Rome on Thursday, Italy's foreign ministry said on Thursday and Ansa news agency reported that one person was seriously injured. [Photo/Agencies]

ROME -- A pair of package bombs exploded at the Swiss and Chilean embassies in Rome on Thursday, injuring the two people who opened them, police and news reports said. There was no claim of responsibility but authorities discounted domestic anarchists or protesters.

Witnesses outside the Chilean embassy said they heard a blast shortly after 3 p.m., sending police to the scene. The ANSA news agency said the person who opened the package was wounded.

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Three hours earlier, a package exploded at the Swiss Embassy in Rome, wounding one person, police said. The Foreign Ministry called it a "deplorable act of violence" against the Swiss.

The explosion occurred when the package was opened by an embassy staffer, who was wounded and subsequently taken to the hospital, said a spokesman at the carabinieri police in Rome. The official spoke on condition of anonymity, saying he wasn't authorized to give his name.

A carabinieri official at the scene told reporters the staffer's hands were seriously injured. He said authorities were still trying to determine to whom the package was addressed.

Italian Foreign Minister Franco Frattini condemned what he called a "deplorable act of violence," and offered Italy's solidarity with the embassy staff and the victim.

There have been growing concerns in Europe about holiday season attacks following a suicide bombing in Sweden and security services' fears of an assault on a European city modeled on the deadly shooting spree in Mumbai, India.

On Tuesday, there was a bomb scare in the Rome subway after authorities discovered a suspicious package with wires and powder under a subway seat. The device though ended up being a fake, with police determining there was no trigger mechanism and that the powder was inert, cement-like material.

The Swiss foreign ministry had no immediate comment on Thursday's explosion.

The Swiss ambassador to Italy planned to make a statement later in the day. At the scene, firefighters and carabinieri massed inside the grounds of the embassy while journalists were kept outside the main gate.