Demonstrators in the Greek capital attacked the U.S. Embassy with molotov cocktails.
The firebombs were hurled during a protest on Wednesday over the killing of African-American George Floyd by police in Minneapolis.
Reuters journalists saw demonstrators throw several flaming objects which erupted into flames on the street towards the heavily-guarded embassy in central Athens. Police responded with rounds of teargas.
The embassy itself was cordoned off with rows of blue police buses.
Demonstrators were holding banners and placards reading “Black Lives Matter” and “I can’t breathe”.
Police sources estimated the number of protesters were more than 3,000.