Iran live updates: IRGC Navy claims attacks on 4 vessels in Persian Gulf

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.

Islamic Revolutionary Guard Corps commander Brig. Gen. Yadollah Javani warned that Iran could target seven critical undersea internet cables passing through the Strait of Hormuz if the U.S. resumes attacks on Iran.

"The Americans and their allies possess significant assets; should they seek to damage our infrastructure, it is only natural that the Islamic Republic would leverage its full capabilities to readily destroy their assets and holdings, including the seven critical internet cables that run underwater through the Strait of Hormuz," Javani said in an interview with the state-run Al-Alam News Agency.

-ABC News' Charlotte Gardiner and Somayeh Malekian

The United Kingdom Maritime Trade Operations (UKMTO) Centre on Wednesday reported an attack on a tanker in the northern Persian Gulf off the coast of Iraq that took place on Tuesday.

"The master of a tanker reports being struck by an unknown projectile, the crew are reported as safe and there is no reported damage or environmental impact," the UKMTO's advisory said. The incident took place 30 nautical miles southeast of Al Faw, Iraq, it added.

In a separate report, the UKMTO said that another tanker was hit by an unknown projectile off the coast of Oman in the early hours of Wednesday. The attack caused a fire which has since been extinguished, it said.