A huge search operation is underway in Iran after a helicopter carrying the country’s President Ebrahim Raisi crashed in the mountainous north-west of the country in heavy fog. Iran’s Foreign Minister Hossein Amirabdollahian was also on the aircraft.The men had been visiting Iran’s remote mountain border region with Azerbaijan to inaugurate a new dam project. Two other helicopters in the convoy made the journey safely.Rescue teams are attempting to locate the helicopter but are being hampered by very poor weather. Iran’s army is reported to have ordered that all resources needed be sent to the search area. The Red Crescent is helping with the search operation. Drones and rescue dogs are being used in the attempt to locate the helicopter. Countries in the region including Turkey have offered assistance with the search. Mass prayers are being said in mosques in Iran. Iran’s state-run television first announced news of what they described as a “hard-landing”. The country’s supreme leader Ayatollah Ali Khamenei delivered a message of calm, saying he hoped that God would return the President to the people. He told Iranians that there would be no disruption to the running of the country.President Raisi has been a key and controversial figure in Iran for many decades, regarded as a hardliner within the Islamic Republic’s leadership. The accident comes at a time of high tension in the Middle East, with the war in Gaza and fears that the conflict could widen. Israel and the United States have accused Iran of backing militant groups including Hamas in Gaza, Hezbollah in Lebanon and the Houthis in Yemen. Recently Iran fired hundreds of missiles at Israel. An airstrike on a military base in Iran was widely seen as Israel’s response to that attack.Foreign Minister Hossein Amirabdollahian is a well-known figure on the international stage, where he has been involved in talks and negotiations about Iran’s nuclear programme. Jane Hill presents BBC News at Ten reporting by Caroline Hawley.