A tentative truce between Israel and Iran is faltering.
Israel vowed to retaliate Tuesday after saying Iran launched missiles into its airspace more than two hours after the ceasefire was supposed to take effect.
State media reported that Iran's military denied firing on Israel.
Explosions boomed and sirens sounded across northern Israel midmorning.
Earlier, both Israel and Iran had accepted the ceasefire plan to end their 12-day war.
Israeli Defense Minister Israel Katz called the missiles a violation of the ceasefire and instructed Israel's military to resume "the intense operations to attack Tehran."