More than 25,000 people participated in the demonstration, which often becomes a focal point for protests against government policies and over ongoing conflicts. It was one of the biggest turnouts in recent years.
Hundreds of police guarded the march to the Embassy of the United States, which provided tacit support to a seven-year military dictatorship that collapsed in 1974.
Demonstrators held banners reading "Resistance for ever!", others waved Palestinian flags. Groups of them later marched to the Israeli embassy.
There was tension between police and protesters in a similar march in the northern city of Thessaloniki.
The junta unravelled in 1974, amid a public outcry over a coup they instigated in Cyprus, triggering Turkey's invasion of the island just days later.
(Reporting by Renee Maltezou; Editing by Toby Chopra)
