Microsoft’s Athens headquarters was attacked last night by gunmen who set fire to the building’s lobby.

According to the Athens’s English-language news site Ekathimerini, three armed men crashed a stolen van into the front of the building and threatened the night guard. They then poured flammable liquid on the floor and set it on fire. The front of the building was damaged and the van destroyed. Fortunately the gas canisters and containers full of flammable liquid did not ignite.

Though no one has claimed responsibility for the attack, Greek authorities are treating it as an act of terrorism. Greece’s anti-terrorism unit is spearheading the investigation.

Microsoft’s Athens office, which employs over 100 people, will be closed today.

The Washington Post managed to get their hands on some raw video from the scene. Check it out below: