Iran live updates: Iran-backed Houthis blamed for Saudi airport strike that killed 12, including American

A dozen people were killed Saturday during a "brutal" attack at the King Khalid International Airport in Riyadh, the Saudi General Authority of Civil Aviation said.

At least one of those killed was an American citizen, the agency said. The U.S. State Department didn't immediately return messages for comment.

The other slain victims included two Bangladeshi citizens, one Egyptian, one Jordanian, one Syrian, one Palestinian, and one Sudanese citizen, according to the Saudi agency.

At least 300 people were injured, the agency said.

The agency said the airport suffered "material damage, the extent of which is currently being assessed," the agency said.

There has so far been no claim of responsibility or comment from Yemen's Houthi rebels. The Iran-backed group claimed attacks on the airport earlier in the week which left three Saudi nationals dead. 

-ABC News' Jamie Dorrington

Iran's Islamic Revolutionary Guard Corps Navy said in a statement on Friday that "a giant ship" carrying LPG, which had intended to pass south of the Strait of Hormuz earlier in the day, was targeted and caught fire.

The statement said that the ship is named NV Sunshine and belongs to Nhat Viet Corporation, adding that it suffered "an extensive fire in the engine room and propulsion system."

The IRGC Navy warned that companies "deceived" by the U.S. would be sanctioned and that "necessary punitive measures will be applied to all vessels of violating companies."

"Henceforth, action against offending vessels will not be limited to the Strait of Hormuz; any vessel traversing an unauthorized route anywhere in the region will be pursued, and punishment will be inevitable," the statement added.

Three Saudi citizens were killed and a number of citizens were injured in Thursday's attacks on Riyadh's King Khalid International Airport, Saudi Arabia’s General Authority of Civil Aviation said in a statement on Friday.

The airport was the subject of two attacks, with the first targeting airport facilities and the second targeting an aircraft belonging to Saudi Arabian Airlines, according to the GACA.

Saudia, the Saudi national carrier, said in an obituary that an airline pilot was killed in Thursday's attack on Riyadh Airport.

The attacks also caused material damage, but airport operations have resumed and air traffic has returned to normal, the GACA said.

The Iran-backed Yemeni Houthi claimed responsibility for the attacks in a statement Thursday.

-ABC News' Somayeh Malekian and Ayat Al-Tawy

President Donald Trump said the U.S. is having "productive discussions" with Iran on Thursday, saying the U.S. will not be attacking Iran before the midterm elections.

"I want to make it clear to everybody that, while Iran is in very bad condition, both Economically and Militarily, and while the Blockade will remain in full force and effect, with Oil flowing in Record Numbers of Barrels through the Hormuz Strait (22 Million Barrels, last night alone, with not one barrel coming from, or going to, Iran!), we will not be attacking Iran at any time prior to the Midterm Elections to be held in the United States on November 3rd," Trump said in a post on social media.