ROME — A letter bomb seriously wounded a senior Italian Army official in Livorno on Thursday, the army said in a statement.

An Italian anarchist group, the Informal Anarchist Federation, took responsibility for the attack, the army said.

The same group was responsible for sending three letter bombs to embassies in Rome in December that wounded two people seriously.

According to the Italian news media, the episode may also have been linked to two other bombs delivered in Europe on Thursday.