AA time-bomb exploded on the night of November 7 outside the headquarters of the Levis Strauss Hellas offices in the Athens district of Halandri, damaging the store front and breaking windows in the building as well as adjacent buildings.

The time-bomb was placed on the ground floor level of the three-story building on 11 Argonauton street, which was closed and unguarded at the time, police said.

No injuries were reported in the blast, which was described by police as of medium force.

So far, no one or group has claimed responsibility for the bomb attack.

On Sunday afternoon, two unknown persons fired some six rounds at the Hellenic American Union's offices in downtown Athens, breaking several windows in the building.

Analysts here believe that the two attacks were part of a number of attacks against US President Bill Clinton's forthcoming visit to Greece next week.

On Thursday, seven cars were damaged at a dealership selling French and German vehicles in an attack claimed by a terrorist group calling itself "Anti-State Action".

ON Friday, police also disposed of a dynamite-packed time-bomb left outside a sporting goods store selling US-based Nike products in a possible attempt to attack American targets prior to the Athens visit by Clinton.

Clinton will pay an official three-day visit to Greece from November 13 to 15. Leftist organizations, students, trade unionists and other groups have said that they would take to the street to protest against Clinton's visit.

Security measures have already been increased at the Athens airport and Athens will mobilize up to 15,000 police officers for Clinton's visit.