Microsoft?s office in Athens have been seriously damaged after armed arsonists forced their way into the building overnight.
Authorities said three armed men threatened the night guard and drove a stolen truck through the entrance. They then poured a flammable liquid on the floor and set fire to it.
The vehicle was also burned in the fire. Police found containers of flammable liquid and camping gas canisters in the truck.
The investigation into the incident is being handled by Greece?s anti-terrorism squad.
Microsoft?s office, which is located in the northern suburb of Maroussi and were more than 100 people work, will be closed on Wednesday.