India, March 6 -- The conflict between Iran and Israel intensified dramatically on Thursday as Tehran launched a new wave of attacks across the Middle East, targeting Israeli territory, American military bases and several regional countries. The escalation came with a stern warning to the United States that it would "bitterly regret" sinking an Iranian warship earlier this week.

The expanding war, now in its sixth day, has drawn in at least 14 countries across the region and beyond. Iranian strikes and retaliatory military actions by Israel and the United States have widened the battlefield from the eastern Mediterranean to the Persian Gulf and parts of Central Asia.

Air raid sirens sounded across major Israeli cities as incoming missil...