Two Russian Emergencies Ministry (EMERCOM) aircraft took off from Zhukovsky airport for Iran’s Tabriz on Monday to assist in the search and rescue operation, following the helicopter crash which killed President Ebrahim Raisi.

Footage shows EMERCOM staff loading a 'Centrospas' aeromobile rescue team’s helicopter onto the IL-76 aircraft, as well as rescuers boarding the plane.

"A joint group of Russian Emergencies Ministry personnel from the Centrospas and Leader Сentre units is on its way to Tabriz. The group includes 47 specialists with the necessary equipment, off-road vehicles and one BO-105 helicopter," the agency’s statement read.

Later, the press service added that both IL-76 aircraft returned to Zhukovsky airport as the search operation had been completed before they had arrived in Iran.

The crash took place in mountains of East Azerbaijan province on Sunday, with the site found by rescuers in the early hours of Monday. All on board including Raisi, his Foreign Minister Hossein Amir-Abdollahian and Governor Malek Rahmati, were reported killed, while the bodies were taken to Tabriz.

The helicopter was travelling from the Iran-Azerbaijan border, where Raisi had taken part in the inauguration of a hydroelectric dam.

Media reports claimed there had been a 'hard landing' during heavy fog, although no official cause has been reported at time of publication.

Russian President Vladimir Putin expressed his condolences to Iran’s Supreme Leader Ali Khamenei and said he would 'always cherish the fond memories of this wonderful man.'

A number of countries, including Azerbaijan, Saudi Arabia, Turkey and Iraq, also expressed support for Iran and offered assistance.