Iran fired a new wave of missile attacks on Israel early Monday, triggering air raid sirens across the country as emergency services reported at least five killed and dozens more wounded in the fourth day of open warfare between the regional foes that showed no sign of slowing.

The latest salvo comes after a weekend of escalating tit-for-tat attacks between Israel and Iran that raised fears of a wider, more dangerous regional war.

Israel identified and struck missile launchers in Iran overnight, the Israel Defense Forces said Sunday morning. "Over the past hour, the IAF completed an additional series of strikes on storage and missile launch infrastructure sties in western Iran," the IDF said in an update on the Telegram messaging app at about 8 a.m. in Israel.