Police say they have intercepted another letter bomb at the offices of Italy's tax collection agency.
The bomb was intercepted on Thursday at an Equitalia office near the center of Rome.
A police official speaking on customary condition of anonymity said agents were working to defuse the explosive.
The director of the office was injured last Friday when he opened an envelope addressed to him containing explosives.
An anarchist group that had also sent a letter bomb to Deutsche Bank in Frankfurt claimed responsibility for that attack.
Police say links with the earlier incidents were under investigation.