Iran and Israel targeted each other with airstrikes early on Saturday after Israel launched its biggest-ever offensive against its longtime foe in a bid to prevent it from developing a nuclear weapon.

Iranian missiles and rockets struck Tel Aviv early on Saturday, while explosions were heard in Jerusalem, Israel’s two largest cities, as hostilities between the Middle East’s two biggest adversaries escalated. The fresh wave of airstrikes came a day after Israel launched its largest-ever offensive against Iran, targeting nuclear facilities, killing top military commanders, and destroying critical infrastructure. In retaliation, Iran fired missiles at Israeli cities, while fresh Israeli strikes triggered explosions in parts of Tehran.

Iran’s assault on Tel Aviv, dubbed “Operation True Promise,” killed one person and injured around 34 others, according to Israeli police and health authorities. In response, Israel launched strikes on Iran under “Operation Rising Sun,” which reportedly killed at least 78 people, mostly civilians, and left over 320 injured.