BERLIN - A package containing a hand grenade was found Monday at the Croatian Embassy in Germany's capital, officials said.

Specialists are investigating whether the device could have exploded, police said.

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Croatia's Foreign Ministry said it was informed by police that the package contained a hand grenade accompanied by a threatening letter.

Croatian President Ivo Josipovic is due to hold talks in Berlin on Thursday with Chancellor Angela Merkel.

A spate of parcel bombings across Europe recently targeted embassies in Greece, Italy and one in November reached Merkel's office.

The ministry in Zagreb said security at the Berlin Embassy had been stepped up since December 23, when mail bombs had been discovered at embassies in Italy.

According to the ministry the package came through a parcel service, but an official thought it to be suspicious and called police. Berlin police, however, said an employee of the Croatian embassy opened the package Monday afternoon and immediately alerted police after seeing what appeared to be a hand grenade.

Police had no immediate comment on who could be behind the suspicious package.

In Greece, suspected members of armed anarchist group Conspiracy Nuclei of Fire went on trial last week on terrorism charges related to a string of attacks with small bombs on Greek politicians, but the group is also linked to a spate of parcel bombings against embassies in Athens and European government officials in November. The attacks caused no injuries, and authorities destroyed most of the bombs in controlled explosions.