A helicopter in a convoy carrying the Iranian president has been involved in an accident, state media is reporting.

State media says President Ebrahim Raisi was on board a helicopter that experienced a hard landing on Sunday.

The Interior Minister said rescuers were still trying to reach the site due to the difficult weather conditions.

According to local media, President Raisi was heading to the city of Tabriz, in the north west of Iran, after returning the border with Azerbaijan, where he opened the Qiz Qalasi and Khodaafarin dams.

Heavy fog is making the search difficult at the site where it is thought that the helicopter may have landed, according to a reporter with Fars news agency.

He said the visibility in the mountainous and wooded area was down to only about five meters.

The area is about 50km to the north of Tabriz.

Ahmad Alirezabeigi, Iranian MP for the city of Tabriz, has told reporters in Tehran that rescue workers have yet to find the location of the helicopter carrying the president.

The MP said the helicopter was also carrying Iran's Foreign Minister Hossein Amirabdollahian.

He added that the other two helicopters in the convoy landed safely.