An employee cleans up a partly burned post office branch in Thessaloniki on Saturday after a group of unknown men emerged from the nearby Aristotle University and threw Molotov cocktails at the building earlier in the day. The dozens of hooded youths also attacked riot police, who responded by firing tear gas. No arrests were made. Police believe the incident is likely to be connected to last week’s arrest of a 21-year-old man in Thessaloniki for throwing a fire bomb at riot officers.