An Israeli airstrike on Friday struck the Shahid Chamran Nobonyad Complex in northeast Tehran, killing at least 60 people including 20 children, Iranian state television reported.
The civilian casualties add to mounting tensions as Israel and Iran engage in direct military confrontation following Israeli strikes that killed six senior Iranian military officials.
Iran retaliated Friday night with "True Promise 3" operation, launching hundreds of ballistic missiles at Israeli military targets.
Israeli forces continued strikes Saturday morning, hitting Tehran's Mehrabad Airport and multiple cities across Iran including Karaj, Zanjan, Hamedan, Kermanshah, and Isfahan.
Iran's Armed Forces spokesman said missile attacks would continue "until the criminal Zionist regime regrets" its actions.
Iran has closed its airspace to passenger flights following the sustained Israeli attacks on Iranian territory.