Riot policemen try to avoid a petrol bomb during clashes in the Athens neighborhood of Exarchia, a haven for extreme leftists and anarchists, Saturday, Nov. 17, 2018. Several thousands people marched to the U.S. Embassy in Athens under tight police security to commemorate a 1973 student uprising that was crushed by Greece's military junta, that ruled the country from 1967-74. (AP Photo/Yorgos Karahalis)