Mediators have achieved progress in getting the United States and Iran back to negotiations, regional officials said Monday, after both sides paused attacks following a period of rapidly escalating tensions. But scattered attacks by armed groups across the region underscored the lingering tensions.

Saudi Arabia said it had shot down drones fired by Iran-backed militias in Iraq that had targeted its petroleum facilities. Iran-backed Houthi rebels in Yemen meanwhile claimed to have attacked Saudi oil facilities as part of a separate but related conflict. It was unclear if they referred to the same attack.

Two drone attacks were reported against a Kurdish Iranian dissident group in Iraq, and Jordan said it had shot down two drones, without saying where they originated. There were no reports of casualties or damage.

Neither the U.S. nor Iran reported carrying out any attacks for three days — a respite after about two weeks of sustained bombardments that had led to increasing fears of a return to all-out war.

The two regional officials, who spoke on condition of anonymity to discuss the closed-door talks, said mediators led by Qatar and Pakistan were working to bridge the gap between Washington and Tehran to return to an interim ceasefire deal that had collapsed after the exchanges of fire.