Police in the Greek capital said in an announcement on Saturday that sixteen people were detained after a protest was held on Friday evening against the metro station construction project at Exarcheia Square.
Some 400 people gathered at Propilea in central Athens at around 19:00, and police asked them to restrict their gathering to only one lane of Panepistimiou Avenue.
At approximately 20:10, police and protesters clashed, with the former using flashbangs and tear gas, and the latter using paint, stones, bottles and other objects while attempting to spread out into Panepistimiou Avenue.
Protesters dispersed, but reassembled at Exarcheia Square at around 11:30 at night, where more clashes erupted with the use of more than 100 molotov bombs against anti-riot police, the statement added.
One car was destroyed during the late-night clashes.