A group of about 15 unidentifed men charged late on Sunday into an office in central Athens which belongd to the Finance Ministry, set fire to the building and left without any police intervention, authorities said yesterday. The culprits, believed to belong to anarchist groups, used crowbars to smash the front entrance of the building, located on the corner of Panepistimiou and Themistocleous streets, before making their way to the first and second floors where the ministry's offices are located. Police said they then set homemade explosive devices, which went off, causing a fire and damaging the stairwell area. Firefighters put out the blaze before it managed to spread, police said. Despite being in a part of the city that has a large police presence, law enforcement did not reach the scene until well after the culprits had left the building. There was a guard on duty at the time the building was raided but he was on the seventh floor, police said.