Iran's Guards Corps' Khatam al-Anbia Central Headquarters warned that any base supporting US military operations against Iranian territory would be a legitimate target for its armed forces, in a statement on July 8.

The warning widens the potential scope of the confrontation to any Gulf facility hosting or supporting US forces, raising the risk to states across the region as Tehran and Washington trade strikes following the collapse of a ceasefire agreed last month. And comes after Iran struck US military bases across the region earlier in the morning. 

The headquarters said the origin of any support for what it called the aggressor US military would be a legitimate target, after US strikes on southern Iran earlier on July 8.

The statement said Iranian army attack drones had struck concentrations of US forces at the Sheikh Isa base in Bahrain from the early hours of July 8, in addition to an earlier operation claimed by the Islamic Revolution Guards Corps (IRGC).

It repeated the IRGC's account that its naval and aerospace forces had struck 85 US military sites at Salman Port, the US Fifth Fleet's area in Bahrain, and Ali Al Salem Air Base in Kuwait in a joint missile and drone operation, and had downed an MQ-9 drone that attempted to interfere.

The headquarters said the US strikes had targeted military and civilian areas in southern Iran and violated the 14-point memorandum agreed between the two sides. The claims of the strikes and their scale could not be independently verified.

US President Donald Trump said the ceasefire was over, telling reporters at the Nato summit in Ankara, "As far as I'm concerned, it's over." US Central Command said it had struck more than 80 Iranian targets, including air defence systems and coastal radar sites, in retaliation for attacks on three commercial ships in the Strait of Hormuz.

The strikes came hours after the US Treasury revoked a licence allowing sales of Iranian oil.

Iran and the US had signed the memorandum last month to extend their ceasefire for 60 days, following months of conflict that began with US-Israeli strikes on Iran on February 28.

British maritime security agency UKMTO said on July 7 an "unknown projectile" had hit a tanker near Hormuz, causing a fire, before two more vessels were struck, at least one by a drone, Newsbase previously reported.

CENTCOM identified the ships as the Marshall Islands-flagged Al Rekayyat, the Saudi-flagged Wedyan and the Liberia-flagged Cyprus Prosperity, all struck close to Oman, according to information IntelliNews has seen.

The Al Rekayyat is Qatari, and Doha denounced the "unacceptable" attack on international maritime navigation and summoned Iran's deputy ambassador. Iran voiced "dismay" over Qatar's accusations in a statement carried by state news agency IRNA, calling the claims "unacceptable."

Oil prices jumped more than 2% in early Asian trade on July 8 to two-week highs, as the renewed attacks revived concerns over global energy supplies and the durability of the US-Iran agreement.

Under the 14-point memorandum, Iran and Oman must hold talks to define the future administration and maritime services of the strait alongside other Gulf states. Maritime traffic had tentatively resumed after the two sides signed the memorandum last month, though Iran has insisted there will be no return to pre-war arrangements under which vessels passed freely.