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 three killed and dozens more wounded in the fourth day of open warfare between the regional foes that showed no sign of slowing.

Nineteen Israelis have been reported killed in Iranian attacks since Friday, while Iran’s health ministry says 224 have died in Israeli strikes.

Both nations have vowed to retaliate “strongly” to each other’s deadly attacks with offensives that have have showed no sign of slowing so far.