Iran's President Ebrahim Raisi was killed in a helicopter crash on Sunday.
The helicopter in which he was travelling crashed amid heavy fog and rain in Iran's East Azerbaijan province.
His death has shocked Iran and the wider world, with some asking why the helicopter was allowed to be flown in such poor weather.
Mr Raisi is not the first head of state to have been killed in an aircraft crash.
Here is a list of previous incidents.
Pakistan President Muhammad Zia-ul Haq, 1988
Pakistan President Muhammad Zia-ul Haq was killed in a plane crash, alongside the US ambassador and several top Pakistani military officials, in August 1988.
The C-130 plane exploded minutes after it took off from an airbase in the Pakistani city of Bahawalpur.
Pakistani and US authorities called the crash an accident, despite speculation.
Rwanda President Juvenal Habyarimana, 1994
Rwandan President Juvenal Habyarimana was killed when his plane was shot down in 1994, in an event widely considered to be the start of the genocide in the country.
Habyarimana – of the Hutu majority – had signed a peace deal with the Tutsi rebels and was flying to the Rwandan capital when a missile hit his plane.
An investigation was launched four years later at the request of the relatives of the French crew members on board.
The investigation was a major point of contention between France and Rwanda.
In December 2016, French judges dropped the long-running investigation. Then in 2020, the appeals court in Paris rejected a request to reopen the inquiry.
President of North Macedonia Boris Trajkovski, 2004
A plane crash, attributed to pilot errors and technical failures, killed North Macedonia’s President Boris Trajkovski and eight others in Bosnia and Herzegovina.
The crash occurred in Stolac in February 2004. According to local media, an investigation released by Bosnian experts blamed the crash on technical problems and errors in procedure by the pilots.
Poland President Lech Kaczynski, 2010
Polish President Lech Kaczynski and 95 others were killed when their plane crashed on April 10, 2010, as it approached the airport in the Russian town of Smolensk. T
The crash was attributed at the time to thick fog, according to local media.
The Polish Foreign Ministry said that the plane caught fire after the crash. Kaczynski’s wife, the head of the Polish army and the governor of the central bank were also on the plane.
In April 2022, a Polish government special commission released a report alleging that the crash was the result of a Russian assassination plan.
The plane crash was the result of “an act of unlawful interference by the Russian side,” the head of the commission, Antoni Macierewicz, said at the time.
The report followed years of allegations made by government officials and was just two months after Russia’s invasion of Ukraine.
Two separate Russian and Polish investigations that had been previously conducted found no evidence of an deliberate assassination attempt.
Former Chilean President Sebastian Pinera, 2024
Chile’s former president Sebastian Pinera died from drowning after his helicopter crashed into a lake in the south of the country in February.
Pinera, 74, was flying the helicopter that crashed into Lake Ranco, about 900km from the capital Santiago, according to AP.
Four other people were on board, three of whom survived the crash, according to the Chilean Interior Ministry.
Bad weather was reported in the area.
