The political council of 17 parties held a second day of protests, demanding Prime Minister Nikol Pashinyan to step down.
The participants gathered near Matenadaran at 5 pm, demanding to lift the martial law and calling on Prime Minister Pashinyan to resign.
The protesters then marched to the National Security Service, demanding to release the detainees.
60 more participants have been detained on suspicion of organizing a rally in violation of the law.
The protests will resume today at Freedom Square.
The unrest is triggered by the signing of a Russian-brokered statement to end the war in Nagorno Karabakh.