Ayatollah Ali Khamenei leads prayers in capital city days after death of Ebrahim Raisi and seven others in helicopter crash

Tens of thousands of Iranians attended the Tehran funeral of the Iranian president, Ebrahim Raisi, whose death in a helicopter crash on a fog-shrouded mountain on Sunday has opened up a potentially volatile moment in Iranian politics.

He died with seven others, including the foreign minister, Hossein Amir-Abdollahian, who was hailed by Hamas on Wednesday as the minister for the resistance.

Three men look set to climb the ranks in a reshuffle including Mohammad Mokhber, who has been named the interim president

The death of the Iranian president, Ebrahim Raisi, has created political turbulence in the country, with uncertainty over who might now rise to the top in the Islamic republic. While the presidency is not the most powerful position in the country – that is reserved for the supreme leader – it holds significant authority.

Here are three men who hold power in Iran:

A country already in political transition could soon be forced to replace more than one leader

• Iran president helicopter crash: rescuers search for Ebrahim Raisi – live updates

The Iranian helicopter crash comes at a time when the country, faced by unprecedented external challenges, was already bracing itself for a change in regime with the expected demise in the next few years of its 85-year-old supreme leader, Ayatollah Ali Khamenei.

In the country’s hydra-headed leadership where power is spread in often opaque ways between clerics, politicians and army, it is the supreme leader, and not the president, that is ultimately decisive.