Two people were arrested and 30 were detained on Thursday during clashes between protesters who are against the construction of a metro station on Exarchia square and police forces sent in the area to guard workers.
Police said a group of local residents, who had gathered since 6.30 a.m., threw eggs, tomatoes and coffee cups against the crews who arrived for work at the construction site.
Riot police blocked them from reaching the square.
The two arrestees will be led before a prosecutor during the day.
The station is to be built directly below the square, with the line running almost parallel to Themistokleous Street. It is one of the four stations on Line 4 in the center of Athens (along with Kolonaki, Evangelismos and Akadimia).