Tensions erupted during two separate protest gatherings and marches held in central Athens on Friday evening when differing groups clashed with each other, police reported.
At Karaiskaki Square in Metaxourgio, a group of far-right individuals gathered to protest the Athens arrival of 'Little Amal', a giant puppet travelling in support of young refugees.
The 3.5-metre-high puppet is being carried from Turkey, across Greece, Italy, France, Switzerland, Germany and Belgium to Manchester in the UK, to raise awareness of young refugees.
Another group of some 200 Αntifa protesters gathered in response.
Police used tear gas to contain minor clashes and also detained three people.
Meanwhile, 300 university students and educators gathered at Propilea to hold a march to Syntagma Square but they clashed with anti-riot police when told to avoid blocking traffic at Stadiou Avenue.
The march was eventually held without closing off road traffic.
READ MORE: Cyprus: Russian tourist lays in the Tomb of St. Lazarus and gets stuck (VIDEO).