The demonstration highlighted the anxiety among the Iranian diaspora as the US-led war intensifies against their homeland.
Meanwhile, online discussions against the imposed war on the country have grown fiercer among Iranians.
All this is happening as fatalities increase in Iran.
Nowruz, the Persian New Year marking the onset of spring and renewal, is also approaching.
Also protests, held under the banner of a "National Day of Action: Stop the War on Iran," were organized by a coalition of anti-war groups.
The events took place in more than 60 cities and smaller towns nationwide.
The ANSWER Coalition, Code Pink, The People's Forum, Palestinian Youth Movement, Black Alliance for Peace, and American Muslims for Palestine coordinated the demonstrations.
Protesters demanded an immediate halt to military attacks, an end to bombings, and prevention of further escalation in the conflict.