, March 1 -- Iran's Supreme Leader Ayatollah Ali Khamenei, who ruled the Islamic Republic for nearly four decades, has died at the age of 86, leaving the country facing an uncertain future with no named successor.

Iranian state media confirmed his death early Sunday without providing details, hours after US President Donald Trump said Khamenei had been killed in a major new attack by US and Israeli forces and urged Iranians to overthrow the ruling theocracy. As reports of his death spread, some residents in Tehran were seen cheering from rooftops.

Khamenei's death comes after years of mounting pressure on his leadership. In one of his final demonstrations of authority, he oversaw the deadliest crackdown of his rule, aimed at crushing na...