The protesters chanted anti-government slogans. Prime Minister Serzh Sarksyan resigned on Monday after almost two weeks of mass street protests, that plunged the country into a political crisis.
However the resignation of Sarksyan, who had been president for a decade, has failed to halt the protesters, who say they consider the whole government tainted by Sarksyan's drive to shift power to the prime minister from the president.
They want opposition leader Nikol Pashinyan installed as interim premier and they also called for early parliamentary polls to take place under a new election law.
Armenia's acting prime minister, Karen Karapetyan, rejected a proposal by Pashinyan to hold talks earlier on Friday to defuse the crisis engulfing the country.
