A helicopter carrying Iranian President Ebrahim Raisi and other senior officials suffered a “hard landing” in “adverse weather conditions” in the country’s mountainous northwest on Sunday, state-run media reported, and search-and-rescue teams worked into the night to find it. The conditions of those on board were not known, authorities said.

“We hope that God the almighty returns the dear president and his colleagues in full health to the arms of the nation,” Ayatollah Ali Khamenei, Iran’s supreme leader, said in a somber statement released on state television Sunday night. Foreign Minister Hossein Amir-Abdollahian was also believed to be on the helicopter.