"No survivors were found" at the crash site of the helicopter carrying Iranian President Ebrahim Raisi, Iranian state news agencies announced, CNN reports.

President Ebrahim Raisi and Foreign Minister Hossein Amir-Abdollahian were among the top officials in the downed helicopter.

An official announcement of their death has not yet been made. Reuters news agency also quoted an unnamed Iranian official as saying that all passengers had died.

Drone footage of the wreckage captured by the Red Crescent and broadcast by state news agency FARS shows the crash site on a steep, wooded hillside, with few parts of the helicopter remaining except for the blue-and-white tail.

Iran's constitution mandates that upon the death of the president, the first vice president assumes, with the approval of the supreme leader, the powers and functions of the president.

The first vice president is Mohammad Mokhber. Officials said earlier that Mokhber was on his way to the area where the president's helicopter crashed.