Iranians were preparing on Thursday to bury their slain leader Ali Khamenei in his hometown of Mashhad in northeast Iran, as new US strikes threatened to trigger a fresh escalation in the Middle East war. But the ceasefire looked increasingly threatened as US Central Command said it had carried out strikes to degrade the ability of Iranian forces "to threaten freedom of navigation" in the Strait of Hormuz -- a key bone of contention in US-Iran talks.