MASHHAD, Iran (AFP) -- 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. The late supreme leader's burial follows a multi-day funeral ceremony that attracted millions of mourners across various cities in both Iran and Iraq. But just as the funeral rites headed into their final day, the United States launched new strikes on Iran in retaliation