New Delhi, March 1 -- Iranian Supreme Leader Ayatollah Ali Khamenei was killed in the United States-Israel attack on Sunday, throwing the future of the Islamic Republic into doubt and raising the risk of regional instability.

Iranian state television and the state-run IRNA news announced the 86-year-old's death on Sunday.

Khamenei's death has created a leadership vacuum, given the absence of a known successor and because the supreme leader had final say on all major policies during his decades in power.

US President Donald Trump, who had announced his death hours earlier, said it gave Iranians their "greatest chance" to "take back" their country by rising up against the Islamic leadership that has ruled the nation since 1979.

However,...