The latest round of attacks, which the United States said was launched in response to Tuesday's assault on three cargo ships transiting the strait, rattled several cities along Iran's southern coast and left some areas without power.
Wednesday's strikes against Iran will be greater in number than the ones carried out on Tuesday, a US official told Reuters, speaking on condition of anonymity.
The latest escalation dented hopes of turning a memorandum of understanding signed on June 17 into a permanent deal to end the conflict.
Iran said on Wednesday it had attacked US military sites in Bahrain and Kuwait in response to earlier US strikes on infrastructure, themselves retaliation for the ship attacks.
