The IRGC again warned the U.S. against the resumption of military action.
Talks between the U.S. and Iran have stalled despite the two countries signing a memorandum of understanding in June, aimed at ending the war that began with joint American-Israeli strikes on the country in February.
The two sides have since exchanged strikes. The U.S. says it is enforcing a blockade preventing any Iranian ships from entering or leaving the country, while Iran claims control over the strategic Strait of Hormuz and continues to claim attacks on shipping transiting the waterway.
Meanwhile, intensified fighting between Saudi-backed Yemeni forces and Iran-backed Houthi rebels in Yemen has seen the latter repeatedly attack Saudi military and oil infrastructure facilities.
See the most recent developments below.
Saudi air defenses intercepted at least five drones over the Riyadh and Madinah regions on Thursday, a Saudi military spokesperson said in statements posted to X.
On Wednesday, the King Fahd Airport international airport in Damman -- on the kingdom's eastern coast -- was targeted in an attack that killed two people and injured eight others.
-ABC News' Othon Leyva
The Islamic Revolutionary Guard Corps Navy claimed on Thursday to have attacked four vessels in the Strait of Hormuz, accusing the ships of navigating an "illegal route" and "transferring oil cargoes from one ship to another."
The ships were hit while in the north-central part of the Persian Gulf, the IRGC Navy claimed, in a statement published by the semi-official Fars News Agency.
The IRGC Navy also reported that three vessels hit naval mines in the Strait of Hormuz on Wednesday night.
The U.S. military has recently been repositioning personnel at U.S. military bases in the Middle East, according to a source familiar with the matter.
The repositioning of forces is similar to what occurred quietly prior to the start of the war with Iran in February, according to the source.
Asked for comment to an NBC report about the reduction of military and diplomatic personnel in the region, CENTCOM spokesman Capt. Tim Hawkins said in a statement, "We regularly move U.S. service members and assets to optimize mission readiness. We do not discuss related movements for operational security reasons. U.S. forces remain vigilant and ready to protect American personnel and interests across the region."
Earlier Wednesday, the State Department ordered the departure of non-essential personnel and family members in Saudi Arabia -- a decision officials say is a direct response to the risk posed by the Houthis.
There have been much smaller posture adjustments at several other embassies in the Middle East — changes officials say are also linked to the Houthi threat and other matters not connected to any plan to resume combat against Iran that the president may be considering.
-ABC News' Luis Martinez and Shannon Kingston
At least one person was killed and eight others injured in an attack on the King Fahd International Airport in Dammam, Saudi Arabia, on Wednesday, according to the Saudi civil aviation authority.
The injuries ranged from minor to severe, the authority said.
"The attack also resulted in material damage, which is currently being assessed," the authority said in a statement.
