The package arrived with no external markings, prompting suspicious embassy staff to call the police, the official said. The embassy was evacuated for about 40 minutes.  French police discovered a low-power explosive device inside, and detonated it under controlled conditions, the official said. The official was not authorized to be publicly named. The Greek Foreign Ministry issued a statement saying the letter was delivered this morning to the embassy, listing the ambassador as recipient. It said it did not list a sender, but the indication was that it had been sent from Italy. In Rome last week, a letter bomb exploded at the office of a tax collection agency, wounding an official. An Italian anarchist group claimed responsibility for the bomb and for sending another explosive earlier in the week to Deutsche Bank in Germany, which was intercepted.