The US hit bridges, energy facilities and a key Iranian port on Friday, expanding its aerial campaign against Iran, and prompting swift Iranian strikes against US allies in the Middle East.

US airstrikes hit bridges in Iran’s southern Hormozgan province, killing at least seven people, Iranian state TV reported. The bridges were a key transit point for Bandar Abbas, Iran’s main port. Further US airstrikes brought down a tower in Chabahar port on the Gulf of Oman. The US also targeted key electrical infrastructure and Iranshahr airport.

Iran’s energy ministry told citizens to reduce their use of electricity and air conditioning after the power grid came under strain due to US strikes on energy facilities. The ministry said areas in the south were experiencing “extreme heat and attacks on power infrastructure” as temperatures in Iran soared.