American forces resumed strikes against Iran on Tuesday, US Central Command said in a statement.

It accused the Islamic Revolutionary Guard Corps (IRGC) of “recent attempted attacks” against commercial shipping in the Strait of Hormuz and “American service members deployed to the region”.

Shortly afterwards Donald Trump warned that Iran would be hit again at “a much harder and higher level” if it retaliated.

The IRGC said the US would regret the strikes and Iranian news agencies reported that retaliatory missile and drone attacks on “US bases and interests in the region” had begun.

The attack follows the first known US strikes on Iran since late July earlier this week, when forces attacked two rocket launchers on Larak Island in the Strait. Tehran retaliated by firing missiles at air bases in Jordan and a drone at the UAE.

On Tuesday Centcom said US forces began striking IRGC targets at 12:00 ET (16:00 GMT). Iran state media reported a provincial deputy governor as saying four projectiles had hit the counties of Chabahar and Konarak.

Iran’s state-run IRIB outlet also reported an attack by US forces on an airport in Jiroft on Tuesday, while the semi-official Tasnim news agency reported that several explosions were heard on Qeshm Island, as well as Konarak and Bandar Abbas.

Trump said Tuesday’s “large and powerful” strikes were a response to Iran’s targeting of a US military base in Jordan, adding the country had “failed” at adding sea mines to the Strait.

He also threatened that a much larger-scale attack was “waiting in the wings”.

The US and Israel launched wide-ranging strikes on Iran on 28 February, with Iran responding by attacking Israel, US bases and allied states in the Gulf, and effectively closing the Strait of Hormuz to marine traffic.

A US-Iran agreement, known as the Memorandum of Understanding, to extend a ceasefire between the two countries was signed in June.

However that agreement has expired, leading to a resumption of hostilities. Both the US and Iran have also fired on shipping, with Tehran targeting vessels it says have sought to cross the Strait without its permission and the US enforcing a naval blockade of Iranian ports.

Washington has also announced a fresh sanctions campaign on 24 August aimed at further isolating Tehran and expanding secondary sanctions against its allies.

Iranian officials and state media have largely dismissed the campaign as a continuation of previous US economic measures, which they argue followed Washington’s military failure in the recent conflict.

However on Tuesday Iranian President Masoud Pezeshkian was quoted by state media as saying if the US returned to committing to the agreement, Iran would reciprocate.