Saudi Arabia and Yemen's Iran-aligned Houthi movement exchanged military attacks on Saturday as fighting expanded around the Red Sea, while the United States refrained from launching air strikes on Iran for the first time in two weeks.
The pause followed 13 consecutive nights of US strikes after the collapse of an interim truce, although Washington gave no immediate explanation for halting operations.
There were also no reported Iranian attacks on Gulf neighbours during the day, even as fighting involving Tehran's regional allies intensified elsewhere.
The Houthis said they targeted Saudi state oil company Aramco facilities in Jizan and Yanbu using ballistic missiles, cruise missiles and drones.
Video verified by Reuters showed a large column of smoke rising from the direction of the Aramco refinery in Jizan.
Trading sources said they had been informed of potential damage to fuel and oil storage facilities in Jizan.
Greek security sources said two ballistic missiles aimed at oil installations in Yanbu were intercepted by a US-made Patriot air defence system operated by the Greek military in Saudi Arabia.
The Houthis also said they would maintain their naval blockade of Saudi Arabia and warned they were prepared to expand military operations if the conflict continued to escalate.
"Our free, faithful and steadfast people will confront it with unwavering resolve and strength."
Saudi Arabia launched strikes on Houthi-held Hodeidah and Kamaran Island, while Yemeni officials said Saudi-backed government forces also struck Houthi missile launch sites, drone positions and weapons depots in Marib and al-Jawf.
Officials said both sides in Yemen's civil war were mobilising forces along front lines, raising concerns that the conflict is intensifying after a ceasefire that had largely held since 2022 broke down this month.
The renewed fighting comes as tensions linked to the wider confrontation involving Iran have increasingly spread beyond the Strait of Hormuz to the Red Sea.
US officials said President Donald Trump continues to favour diplomacy despite warning that Iran would face consequences if negotiations fail.
Trump also said the United States and Iran were engaged in talks, although he maintained Tehran was not yet ready to reach an agreement.