Chechen President Akhmad Kadyrov was killed in an explosion that rocked a stadium in Grozny, capital of Russia's breakaway Chechen Republic, on Sunday, the Interfax news agency reported.
The blast occurred underneath a VIP-seating area in the Dynamo stadium during a ceremony marking Russia's 59th anniversary of victory over Nazi Germany in World War II.
It is not clear now how many people were killed or injured in the incident. Media reports said earlier a numerous number of people were injured.
General Valery Baranov, head of the Joint Army Command of the North Caucasus, were also among the injured, Interfax said.
The 52-year-old Kadyrov, a one-time Muslim cleric, was elected the republic's president earlier this year.
Russia's independent NTB TV channel reported that people in the stadium were being dispersed with the help of local servicemen.
Russia has been fighting separatists in the northern Caucasus region of Chechnya since the early 1990s.