Polish President Lech Kaczynski has been killed after his plane crashed in foggy conditions in western Russia.
Here is a list of leading politicians who have died in previous air accidents.
1936, ARVID LINDMAN
Swedish prime minister killed when Douglas DC-2 crashes into houses in Croydon, London, while attempting to take off in thick fog on 9 December.
1943, WLADYSLAW SIKORSKI
Prime minister of Poland in exile killed when B24C Liberator crashes on 4 July into the Mediterranean shortly after taking off from Gibraltar.
1959, BARTHELEMY BOGANDA
Central African Republic (CAR) president killed on 29 March when Atlas flying boxcar exploded in midair over Bangui, CAR.
1961, DAG HAMMARSKJOLD
UN secretary-general killed when Douglas DC-6B crashes into jungle in Zambia on 17 September.
1966, ABDUL SALAM ARIF
President of Iraq killed on 13 April when helicopter crashes, reportedly in a thunderstorm.
1977, DZEMAL BIJEDIC
Yugoslav premier dies when Gates Learjet crashes into a mountain during a snowstorm on January 18.
1981, JAIME ROLDOS AGUILERA
President of Ecuador killed when Beech Super King Air 200 FAE-723 crashes in poor weather on May 24.
1981, GENERAL OMAR TORRIJOS
Panamanian leader killed when Panamanian Air Force plane crashes under suspicious circumstances on 31 July.
1986, SAMORA MACHEL
Mozambican president killed when Tupolev-134A crashes in a storm while trying to land at Maputo on 19 October.
1988, GEN MUHAMMAD ZIA UL-HAQ
Pakistani president killed when Pakistani Air Force Lockheed C-130B crashed shortly after taking off from Bahawalpur on 17 August.
1994, JUVENAL HABYARIMANA AND CYPRIEN NTARYAMIRA
President of Rwanda, Habyarmama, and President of Burundi, Ntaryamira, killed when Dassault Facon 50 9XR-NN shot down by missile while approaching Kigali airport on April 6.
2004, BORIS TRAJKOVSKI
Macedonian president killed when Beechcraft Super King Air 200 Z3-BAB crashes while attempting to land in poor weather at Mostar on 26 February.
2005, JOHN GARANG
Sudanese vice-president killed when helicopter crashes in poor weather into a mountain range in southern Sudan on 30 July.
2010, LECH KACZYNSKI
Polish president killed when Tupolev-154 crashes in foggy weather when approaching Smolensk airport in western Russia on 10 April.