Iran launched a new wave of missile attacks on Israel early Monday, triggering air raid sirens across the country as emergency services reported at least three killed and dozens more wounded in the fourth day of open warfare between the regional foes.

Israel has struck Iran’s nuclear sites and military leaders, and Tehran has retaliated with missiles.

The sky over Tehran was engulfed in smoke and flame on Sunday after the city’s main gas depot was struck during Israel’s latest wave of attacks on Iran.