Several explosions were heard in Saudi Arabia’s capital of Riyadh on Thursday, including a large blast at the city’s international airport, a witness told The Associated Press, a day after the kingdom said an attack there killed one person and wounded others.

The blasts had an immediate effect on markets and oil prices as the price of crude jumped, and Saudi Arabia slid further into the latest front in the Iran war. CNN reported.

Iran-backed Houthi rebels in neighboring Yemen claimed responsibility for the new attack on King Khalid International Airport, saying the ballistic missile caused damage but giving no evidence. The Saudis had no immediate comment about the claim.

spokesperson for the Saudi-led coalition fighting the Houthis, Maj. Gen. Turki al-Malki, said they intercepted and destroyed two ballistic missiles launched by the Houthis toward Riyadh, along with a ballistic missile fired toward Khamis Mushait, in the southwest near the Yemen border.

The Houthis have repeatedly claimed attacks against Saudi airports, military and oil facilities in recent days. Early Thursday, the rebels warned global airlines “for the last time” about the potential consequences of operating in Saudi airspace, which it called a theater for its military operations.

In their new statement, the Houthis also warned people in Saudi Arabia to stay away from oil facilities that “represent targets for our forces” as the rebels press a blockade they recently imposed against the world’s top oil exporter.